Stan Wawrinka is confident he can raise his game further after he beat Viktor Troicki to reach the quarter-finals of the French Open on Sunday.
The defending champion marched into the last eight with a 7-6 (7-5) 6-7 (7-9) 6-3 6-2 victory on Court Philippe Chatrier to make it five wins out of five career matches against the Serb.
Third seed Wawrinka made 50 unforced errors, but came up with 67 winners to stay in contention to win a third grand slam title.
The world number four was content with the manner in which he ousted Troicki and believes there is more to come from him in Paris.
"For me, it was a great win, a great match, a very robust match," said the Swiss, who will face Albert Ramos-Vinolas in the quarter-finals after the Spaniard shocked Milos Raonic.
"The conditions were a bit difficult. It was a player I know well. Sometimes he plays really well; sometimes he yields more," Wawrinka said of Troicki.
"So I tried to tweak the little mistakes to kind of fine-tune and clean up my game. But I would say that the main thing is mentally. I managed to stay very calm, I didn't get excited, or irritated, even though I lost the second set.
"I go on to the court to win, not for the style. I do the job. I'm there to win the match, and it's really positive to see that of course I can play better still. That's no surprise.
"The important thing is not to give your best tennis style; it's to win the match. That's [why] I'm happy with the manner in which I played this game. I managed to play better, I managed to find solutions."
Wawrinka, who upset Novak Djokovic in last year's final, acknowledged he will be expected to dispatch Ramos-Vinolas and reach the semi-finals.
"I know that I may be able to tighten a few nuts and bolts here and there when the going gets tough, to improve even more," he said.
"But I'm playing well. I'm enjoying. I'm winning matches. I'm in a quarter-final now. Of course on paper I'm the favourite against Ramos.
"I know what to do to win, and then I'll just see how it goes, and at the end of the two weeks I'll take stock and see whether I was really good or just okay."