An emotional Stefanos Tsitsipas said losing his five-set thriller with Stan Wawrinka at the French Open on Sunday was the “worst feeling in tennis”.

The 20-year-old Greek star missed out on a quarter-final against Roger Federer as Wawrinka dug deep to win the longest match of this year’s tournament 7-6 (8/6), 5-7, 6-4, 3-6, 8-6 after five hours and nine minutes.

The sixth seed, who reached the Australian Open semi-finals earlier this year, cut a devastated figure in his press conference, struggling to hold back the tears.

“Worse thing in tennis. It’s the worst feeling ever. Especially when you lose. You don’t want to be in my place,” Tsitsipas said.

“I feel exhausted. I don’t know. Never experienced something like this in my life.

“I feel very disappointed at the end. (It’s been a) long time since I cried after a match, so emotionally (it) wasn’t easy to handle. I will try to learn from it as much as I can.”

But Tsitsipas added that he had no idea what he could actually learn from the defeat, which was completed by an incredible Wawrinka winner from yards behind the corner of the court.

“I have no idea. My mind is so empty right now. I cannot even think, so I don’t know.”

Three-time Grand Slam champion Wawrinka saved 22 of 27 break points in the match, as Tsitsipas let all eight of his break opportunities in the deciding set slide by, and his opponent did not garner one until he brought up match points in the 14th game.

“I was so close, so close,” said Tsitsipas.

“I give him room to do whatever he likes, all those break points. So many break points. So many. Didn’t play. I was expecting someone else to play it for me. I didn’t play.”

It was the longest match of both players’ careers and the third-longest at Roland Garros in the last 20 years.

Tsitsipas played well for long periods of a high-quality encounter, finishing with 61 winners and 48 unforced errors, while winning one point more than Wawrinka.

But despite the heartbreaking and exhausting manner of the defeat, the world number six, who started the year ranked 15th, said he would not want men to play fewer sets at Grand Slam tournaments.

“Shouldn’t change anything. It’s fine the way it is.”

Tsitsipas will attempt to pick himself up before the start of the grass-court season – likely to head into Wimbledon as one of the favourites for the title behind the ‘big three’ of Federer, Rafael Nadal and Novak Djokovic.