Alexander Zverev endured a horrific injury that left him screaming on the ground during Friday night's French Open semi-final against Rafael Nadal. The German was forced to pull out of the match late into the second set in a thrilling encounter that could have gone in either direction.

Zverev had to be taken off the court with a wheelchair after twisting his ankle during an intense rally. A concerned Nadal came over from the other side of the court after Zverev was left screaming in pain and clutching his ankle. The medical team acted quickly to help the German, but it was clear he could not continue and he soon returned in crutches to bid farewell to the crowd at Philippe Chatrier.

Alexander Zverev
Moment of horror: Alexander Zverev on court as a concerned Rafael Nadal looks on AFP / Anne-Christine POUJOULAT

Nadal was leading 7-6 (10-8), 6-6 at that point, but Zverev was showing great potential against the 13-time French Open champion before he retired. The first set was hard-fought, with Nadal having to come back from a break down to win on the tie break.

In the second set, Zverev again took an early break before Nadal broke back immediately after. The two players kept exchanging breaks and they were at a deadlock when the tragedy happened.

Zverev has since taken to social media to share an update. He admitted that it was a "difficult moment" for him on the court, and described his injury as "very serious." He said that his medical team is still checking on his condition and he will keep his fans updated.

Meanwhile, Nadal admitted right after the incident that it was difficult to see his opponent crying after getting hurt. "If you are human, you should feel very sorry for a colleague. To see a colleague like this, even if for me it's a dream to be in the final, is not the way that we want it to be," he said.

Indeed, Nadal is now on course to make history at Roland Garros once more. Not only will he be going for his 14th French Open crown, he is also gunning for a record-extending 22nd Men's Singles Grand Slam title.

His opponent, Casper Ruud, is also hoping to write history in his first Grand Slam final.

Rafael Nadal and Alexander Zverev
All over: Alexander Zverev walks with crutches back on to the court AFP / Anne-Christine POUJOULAT