Sustained boos and whistles rained down from the Court Philippe Chatrier stands after the American shushed the fans repeatedly, having beaten Arthur Rinderknech in four sets under the lights.
As he was preparing to do his post-match interview, Fritz kept his cool as he came under fire, barely able to exchange words with court-side interviewer Marion Bartoli.
"I'm sorry I actually can't hear you," he told the former Wimbledon champion.
"The crowd was so great honestly...that I had to let it fire me up. They cheered so well for me I wanted to make sure I won," he added, having ended the French presence in the singles draws at Roland Garros by beating the last home favourite.
The crowd is fickle, corporate seats are often empty at lunchtime but when a French player needs support spectators turn the usually quiet courts into a wild arena and the claycourt Grand Slam provides an atmosphere unmatched at other majors.
This is exactly what Fritz experienced in his match against Rinderknech, like others before him.
When the crowd pick on a player, it can become exceptionally unsettling, as Martina Hingis notoriously experienced in the 1999 final against Steffi Graf.
Booed and jeered by the fans after disputing a line call while 6-4, 2-0 up, the Swiss lost her composure and the contest before being booed again after match point.
