The 24th-seeded Wawrinka won three straight tiebreaks to beat Dimitrov 7-6(5) 7-6(4) 7-6(8) in the 'Bullring' in Paris, and said he took heart from being able to "increase my tennis in the right moments."
The 2015 Roland Garros champion, who has also won Slams in Australia (2014) and the United States (2016) has been clawing his way back up the world rankings after he fell out of the top 250 following his operation in 2017.
"I'm at my best level since my surgery," Wawrinka told a news conference.
Asked whether he was thinking about lifting the Musketeers' Cup again, he replied with a smile: "I'm far away from thinking about that here. Do I think or believe I can do it? Maybe. Who knows? But to win a Grand Slam, it's a long road."
Wawrinka faces 20-year-old rising star Stefanos Tsitsipas in the fourth round.
The Greek tyro is seeded sixth in Paris after a hot run of results this year, including reaching the Australian Open semi-finals and claycourt finals in Estoril and Madrid.
"He's a really young player, already at the top of the game, already winning a lot of matches, already beating the top players," Wawrinka said of his next opponent.
"He's an incredible player, and he's been able to beat Roger in a Grand Slam (at the Australian Open), Rafa on clay (in Madrid). So he's present and it's going to be a very difficult match tomorrow."
(Reporting by Richard Lough, editing by Pritha Sarkar)
