Watch: French tennis player falls, hits unbelievable winner while sitting down

Many tennis fans probably weren't familiar with the name Quentin Halys before Friday.

During his 6-1, 7-5 quarterfinal win at the EFG Swiss Open Gstaad, however, the 27-year-old Frenchman had one particular winner midway through the first set that will be replayed on highlight reels for years to come.

The moment that Halys tripped, it seemed like he was destined for trouble and a 40-30 score in the fifth game of the opening set. Instead, the 27-year-old miraculously kept his composure while on his backside, setting himself up to deliver a perfect crosscourt forehand that his opponent (Brazil's Gustavo Heide) was barely able to return and ultimately hit out of bounds.

By the time Halys actually made contact with the ball, he was essentially in a plank position on his left side, making the shot all the more improbable.

Halys has never been ranked higher than 61st on the ATP singles rankings and is currently unranked. Halys is fresh off his best performance at a Grand Slam, as he made third round at Wimbledon for the second straight year earlier this month.

Halys will next play fifth-seeded, 37th-ranked Jan-Lennard Struff in a Swiss Open semifinal on Saturday.