"I gave everything. I'm very proud of the way I played, the way I fought," said the 23-year-old Greek after 3:23 of the match.
Semi-finalist last year, he will face the Italian Jannik Sinner (10th) on Wednesday to find the last four.
"I knew it would be physical, that you would have to be patient. I knew the public support would be important," he added.
The match, spectacular and very tight, tipped in favor of the finalist of the last Roland-Garros at the end of the 5th set when he broke for 5-4 and then served for the match.
He did not miss the opportunity.
Fritz was playing his first round of 16 in a Grand Slam at the age of 24.
© 2022 AFP