Q. It seems like after 5-all you had no problems anymore.

RAFAEL NADAL: Problems? There is always. There is always some key points of the match that change the dynamic of the match. Is true that I was lucky in the first set to have the set with me because was very dangerous. I think Kevin was playing very aggressive from the beginning, going for the winners every shot. He had the breakpoint before in the 3-2 or 3-All, I think. Then with the 5-All I was lucky, sure. I played two forehands down the line, because was not an easy forehand because he pushed me. I changed the direction, but I can miss that shot, no? Then a few good serves, but especially the ace again. Yeah, but in general, even if he had that chances in the first set, even in the first set seem that he was having more chances than me, I was playing better than the days before, no? I felt myself with better rhythm in the legs, better rhythm with my forehand. So in general, I am very happy the way I played today. The way that I improved my level is not the most important thing; obviously the victory is.

Q. Until the game that you broke him in the first set, you had only won one point on his serve. Was it a matter of you figuring out the serve, or did his level of serving drop?

RAFAEL NADAL: I don't know if you saw that, but I changed completely the position on the return. I was returning very close to the baseline. Is easier to start more aggressive and make the transition aggressive to defensive than defensive to aggressive. So is something that I talk before the match, and we decided to go close to the baseline in the beginning. Then if was not working, try to play more points. I had that feeling that I need to make him feel that he needs to play a winner to win the point, no? Because before my feeling was he was winning too many points only with the serve. So I tried to change that at the end of the first set. I was able to have some good returns. One very good one, but then the other ones, just put the ball inside the court and then try to let him think a little bit more than what he was doing until that moment. That's what changed the dynamic of the games on the return. Very favorable way for me.

Q. Tell us how you get out of these difficult positions. What is going through your mind in those moments?

RAFAEL NADAL: I try to think point by point. I know with Love-40, losing that games with the first set and losing the first set against a player, a very good player like Kevin, he has big serve, and then he's able to play good from the baseline, pushing you from the first ball. So I know that I going to play with lot of pressure during the rest of the match if I want to have chances to win. And I fought point by point. I just tried to change a little bit the way I was serving. I served a little bit more aggressive. It's true that I had two forehands down the line, as I said before, that can miss. But for the rest, I had two good -- Love-40 was that forehand down the line, but then in the 15-40 and the 30-40, two good serves to the body. Something that I was not serving very often since that moment, so I changed that. Then breakpoint I changed the direction and serve probably the fastest serve for me this tournament, 205 ace in the middle, no? So just try to play with the right decision, right determination, and I did. Worked well. But sometimes works well, sometimes isn't.

Q. A lot of other players get tight in these moments. You don't seem to get so tight, so worried.

RAFAEL NADAL: I am (smiling).

Q. You said a week ago before the tournament that you didn't consider yourself one of the favorites to win it, but ask you in a week if you're still here. You're still here. How do you feel about your chances to go further now with four wins under your belt?

RAFAEL NADAL: I am one of the eight. That's the most important thing, no? I am in the last eight of the tournament. Seriously, for me, I cannot talk about that. I never talked during my career about that. But especially in this moment when you are coming back after a period of time where you were not on competition and you're going to play a very tough player like Tomas Berdych that he started the season great playing very well in Doha, and now he's here in quarterfinals. I don't know if he lost a set. I don't think so. He's playing great. Will be a very tough opponent, no? But for me quarterfinals is a great result, talking seriously. Arriving here, losing in the first round of Qatar, not playing matches for the last seven months, to have the chance to be in quarterfinals again here is a very positive thing for me. I'm very happy for that. I am sure that going to help me for the next events. For sure I going to try my best after tomorrow. I am not a person that I am happy like this and that's it. No. I try to play better and better every day. If that happens, I hope to keep having chances for the next match. But today is a day to be happy the way that I improved my level of everything, talking about tennis, all the things I have to do on court. I was closer today. Even if I played the first two sets the other day well, today I was much closer what I have to do to try to have success.

Q. How far do you feel you are from your best shape? 60%? 70%?

RAFAEL NADAL: That's not mathematics. You cannot say number. Doesn't matter at the end. I am in quarterfinals. I am feeling better every day. You don't know. Today I was at very, very high level winning against Kevin Anderson. I don't know which ranking he has.

Q. 15.

RAFAEL NADAL: Winning against the No. 15 of the world in straight sets, would be very arrogant if I say I'm not a very high percentage. Happy the way I played today. Is the first day that I felt that I was playing at the level that I want to play and the way that I want to play. Let's have a chance to practice tomorrow, keep doing well the things I did today, and then try to arrive for the next match with the highest energy possible and try to be ready for it. I know it's going to be very tough.

Q. You mentioned Berdych earlier. You have an incredible record against him. I think you've won your last 17 matches, 37 out of the last 40 sets. Why do you think you have been so successful against him over the years?

RAFAEL NADAL: Doesn't matter what happened in the past. Is different story this time. Different moment for me; different moment for him. So the way we arrive to that match don't going to affect what happened in the match. I'm sure of that. He's a great player. I have success against him, but I have the chances to lose against him. I remember 2012 probably I had a very, very tough match against him here. It was close to be two sets to love down. He's a player that is top level.

Q. What is the meaning of what you're writing on the lens of the camera?

RAFAEL NADAL: Doesn't matter. Is stupid thing. With my friends, that's it.

Transcript: AustralianOpen.com

Q. How did you day yesterday go and how did you feel today on the court?

RAFAEL NADAL: Yesterday was okay. Seriously I feel that I was in terms of legs I wake up in the morning better than what I thought. In terms of, you know, I was still a little bit dizzy yesterday. I think I lost lot of fluids the other night. But in general I was not very, very bad. Knowing that I going to play tonight, I know -- I hope that I -- I thought I going to be ready for tonight, no? Happy the way I was physically on court tonight. Obviously happy the way I played the first two sets. Then the third play with more mistakes, but all is part of the process that I am doing. It's normal to play every day with a little bit more ups and downs when you are out for a while.

Q. Was it focus in the third set or because it goes on and on the body needs to adjust to compete again?

RAFAEL NADAL: No, it's a little bit about confidence, a little bit about the feelings on everything. You know, when you are on the tour, playing better or playing worse, you make some mistakes. But normally that don't affects for the next balls, no? But obviously when you're not there on competition for a long time, without having that feelings for a while, you need to readapt your mental part, your confidence again to the court. Happens when I have some mistakes that I am losing little bit of confidence for a while. It's positive that at the end of the match I play with the right position, right determination again. But it's true for that games I was having more mistakes than usual with my forehand again.

Q. You saved all seven breakpoints he had against you. That must please you.

RAFAEL NADAL: Yeah, it's true the other night, at the end of that fifth set that I play with the right determination, even if I was very tired, some good balls, good shots. Today again with the breakpoint I think I really served. My serve worked well on the breakpoints. I had one lucky break, that was at the net, with my forehand. But the rest of the points I played with determination, going to the net, having some good serves. The last game, I am happy the way that I lost the first match point trying to go for the winner with my forehand. Even if I had the mistake, I think it was the right thing to do in that moment. Happy to be able to take that position in that moment. With 6-5, never easy. Then with the next point I was able to finish with the forehand, no? I play with the right determination in the right moments. That gives me confidence and a way how to play for the future.

Q. You played some amazing shots tonight. Even after all this time, do you sometimes surprise yourself with some of the shots you play?

RAFAEL NADAL: Well, when you are on the confidence, you feel that that shots comes without thinking. When you are little bit on that process, all the shots are important for you. When you are making good shots, always surprise you a little bit. But is true that for two sets I was able to adjust very well the balls, playing some very good forehands down the line. If I want to have chances to keep being competitive in this tournament, I need to play this way. I need to play more aggressive. I need to play with that determination. I really hope the suffer of the other night and then the way that I played today going to help me for the next round. Going to be a big opponent, no? Big server. Kevin is very aggressive player. Going to be a big, big test for me. Very tough match.

Q. About the conditions, you played in the night. How do you feel if your next match is going to be played in the daytime, playing Kevin Anderson?

RAFAEL NADAL: I don't know. All my career, if the conditions are not very humid, I like the faster conditions than slower conditions, no? I feel during all my career I like when the ball is faster, flying quicker through the air, and has more topspin. Always help me more my game than when we play during the night. As I say before, seems like the next couple of days will not be very hot. That's what I saw yesterday in the predictions. So after what happened the other day, for me is not negative thing.

Q. You said on the court that you don't like to sleep very much. Were you joking or was that a serious answer? A lot of athletes like to sleep a lot because they need to.

RAFAEL NADAL: No, I never like to sleep a lot, no. It is obvious when I am on competition and when I am practicing a lot I always sleep that eight hours that I need. But, no, I am not big fan of being relaxed on the sofa, watching TV, sleeping a lot of hours. I like activity. I like the sport. I like to do things. During all my career, during all my life, I was that way. Is true that the last couple of years I take the life little bit more easy without doing that many things that when I was 18, 19, 20, 21. But even like this, I am a person who likes to do things.

Q. There's been some thoughts about changing the schedule of the tournaments. Like between the French Open and Wimbledon, an extra one week this year. There's been talk that the Australian Open would also benefit from a later start, say in February or March. Your thoughts on that? Would it benefit the players if you had more time for preparation for the Australian Open if it starts in February or March?

RAFAEL NADAL: Is difficult to imagine about these kind of things. I don't know if in February the conditions are warmer here even. I don't know if that's a good idea. Is not very healthy when you are playing under 38 degrees or 36 degrees or 40. Is not the ideal thing. But anyway, is true that have such an important tournament that early in the year, is true that --

Q. It would give you two or three weeks extra preparation, everyone.

RAFAEL NADAL: Sure, is always that for everybody. Is better to have, for example, more than one tournament before the Australian Open, no? It would be great if we are able to go early with two more weeks would be great for different facts, no? For us, is important to spend the new year at home. Is important to spend Christmas at home with family. That dates are, you know, very important. Players have family. Players have small kids. You want to spend that time with them. With that calendar, is tough to have and enjoy this period of time with your family. Is true that if we went two weeks, better for that. But at the same time, is better to play one tournament or two tournaments before Australian Open. Would be great. Two tournaments will have the right period of time before the tournament to play. But today we are talking for talking, because I don't see a change in that calendar for the future.