"I saw that I could increase my tennis level in the right moments, in important moments," Wawrinka told reporters. "I want to continue, and I will try to do that tomorrow.
"He's (Tsitsipas) a really young player, already at the top of the game, already winning a lot of matches, already beating the top players, making his way to an even better career... I'm happy to face this challenge."
This will be the eighth time Wawrinka has reached the last-16 in Paris. Sixth seed Tsitsipas, meanwhile, became the first Greek player since Lazaros Stalios in 1936 to reach the last-16 at the French Open.
In a match carried over from Friday due to facing light, Tsitsipas beat Serbian Filip Krajinovic 7-5 6-3 6-7(5) 7-6(6).
Tsitsipas and Wawrinka have practised together a few times but this will be their first competitive meeting.
"He always looks like he gives himself a lot of time to play. He doesn't feel like under pressure. So he's playing the game well," Wawrinka added.
In the day's other big matches, defending champion Rafa Nadal and third seed Roger Federer will both meet Argentine opponents on Court Philippe-Chatrier. Federer takes on Leonardo Mayer before Nadal plays Juan Ignacio Londero.
(Reporting by Hardik Vyas in Bengaluru; editing by Tony Lawrence)
