Stan Wawrinka speaks to the media following his 7-6, 6-3, 3-6, 7-5 victory against Yen-Hsun Lu.
Q. Pretty solid start. What happened then in the third set?
STAN WAWRINKA: Generally I'm happy with my match. He's always a tough player to beat, especially when he start to play well.
I lost a little bit my focus on my serve. Got broken two times a little bit when I was up 40-15 and 40-Love. I don't know, was just a little down during the match.
But generally I'm quite happy with the victory.
Q. It seemed like you had something maybe with your back. Something bothering you?
STAN WAWRINKA: No, my body is okay.
Q. The first time in five years you've made it to the third round. You must be pretty excited about it.
STAN WAWRINKA: Well, I'm happy with the win today. But for me to lose in the first round or third one doesn't change. It's the same.
I want to go further. It's important that I'm playing well. I'm confidence with my game. I will have a tricky match against Istomin. He's a really tough player on the grass courts. I already lost against him. It's going to be interesting to play him in two days.
Q. Any particular reason what made it tougher for you to play on grass in the past?
STAN WAWRINKA: I had some tough loss last year against Lleyton. It's never easy to play him. I lost against Istomin, Bolelli.
Grass is tough. It's tough to change quickly from clay court to grass, especially for my game. I need a lot of time on the grass. In past years maybe I didn't have enough practice, enough time.
This year I had the chance after losing early in French Open, I had a wild card in Queen's, so I've been playing on grass since, almost three weeks now. I'm feeling really confidence with my game. I think that make a big difference.
Q. Have you ever talked to Roger about playing on grass? He knows a thing or two about it.
STAN WAWRINKA: We used to practice a lot. We did actually this year. We always try to practice here together.
We never really talk about that.
Q. Will you watch his match at all now?
STAN WAWRINKA: If I have time after, for sure I will watch. I always watch when I go back home. It's going to be interesting. It's going to be a nice match, for sure.
Q. I would like to ask you something about the World Cup. Switzerland will be the next opponent of Argentina, and Messi.
STAN WAWRINKA: What is the question about Messi?
Q. What is your opinion about him?
STAN WAWRINKA: He's an amazing player, for sure. Nothing to say.
I think we played well last night. It was an important match for us. The players showed they have everything to win. They won in a good way. They were playing well.
But it's going to be an interesting match against Argentina. It's going to be a new match. It's not in the group anymore. It's going to be tough one, but we'll see. I'm excited to watch it.
Q. You mentioned the last match against Istomin here. It's been a while since then. Is there something you can take from that match?
STAN WAWRINKA: Not really from that match, but more from his game. I know how he's playing. We played quite a few times together. He's a tough player.
He's playing flat. He's returning well, serving well. Never easy to play, especially on grass. He had his best result in Grand Slam I think here in Wimbledon. So it's going to be interesting match.
Q. Is it useful for your progress in the tournament to have had a real test today rather than sailing through in straight sets?
STAN WAWRINKA: No, it's always better to win easy.