Defending champion Stan Wawrinka feels his game continues to improve after brushing aside the challenge of Taro Daniel at the French Open.

Wawrinka had a difficult opening match at Roland Garros as he was pushed to five sets by Lukas Rosol but he had no such problems against Daniel, posting a straight-sets win.

His 7-6 (9-7) 6-3 6-4 victory makes it six in a row for the world number four, building on his triumph at the Geneva Open last week.

"So far, I feel great, for sure," the Swiss told a media conference. "There is a lot of positive for me winning Geneva, taking a lot of confidence from that week.

"I normally also don't like to play the week before Grand Slam. That's not normally what I do.

"But when they came with the tournament in Geneva, it was something important for me to try to do it. It's home. It's a big change in your career when you have a tournament at home.

"That's what I did. I changed a little bit the rest of the schedule to make it the best schedule possible for the French Open, and so far I think I'm feeling good.

"I had a tough first round, winning five sets wasn't easy, but was really positive because the fight was great. Mentally I was there, also.

"It was a tough three-sets match, but I think I did the job I had to do. I'm happy. I think I'm playing better and better."