Zverev had taken exception to Fils’ decision to start delivering underarm serves, while Fils was left raging with a call after his serve was called in but a review proved it had landed out of the court.

The players confronted each other after the conclusion of a game, with the furious Fils seen marching over towards Zverev’s chair courtside. The umpire stepped off his own chair to separate them and even physically restrained the Frenchman at one point to keep him on his side of the net.

The crowd began to cheer when Fils missed his serves, presumably taking the underarm serve as a sign of disrespect towards Zverev.

The tension continued to bubble away into the final set before Fils clinched a memorable maiden ATP 500 title of his career, prevailing 6-3, 3-6, 7-6 (1) in a three-and-a-half-hour marathon. Zverev turned away from his conqueror at the net after sharing a frosty handshake, with Fils left wondering why the world No 4 appeared to still be angry with him.

Afterwards, an emotionally-drained Fils clarified why he had resorted to underarm serves, citing cramping in his muscles which appeared to restrict his serving style.

“I did everything to win this match. At 5-5 in the turn, I’m cramping, I did an underarm serve because I can’t serve,” Fils said on court after the match. “[The] crowd take it badly… I don’t care. I’m winning and that’s it.”

It seems the players made up in good time, however, with Zverev spraying champagne during the celebrations and laughing with Fils whilst soaking him with the sparkling wine beverage.

The 20-year-old has enjoyed a fine breakthrough season on the ATP Tour, climbing to a career-high rank of 20th in the world and becoming the French No 2 behind Ugo Humbert.

He will now focus his efforts on competing at the Paris 2024 Olympics in his home city as part of France’s tennis lineup. He joins Humbert, Gael Monfils, Corentin Moutet in the men’s side, with Caroline Garcia, Clara Burel, Diane Parry and Varvara Gracheva on the court at Roland Garros.

There, he could yet meet Zverev again as the 27-year-old forms part of the Germany lineup with Jan-Lennard Struff, Dominik Koepfer and doubles duo Kevin Krawietz and Tim Putz. Tatjana Maria leads the women’s charge with Tamara Korpatsch and Laura Siegemund.