There was confusion at the Qatar Open on Thursday as Daniil Medvedev suddenly retired in the middle of his quarter-final match.

Felix Auger-Aliassime took the first set 6-3 and headed to his bench for the changeover while Medvedev approached the chair umpire.

The official then announced that Medvedev had retired, and the No. 4 seed walked off court without shaking his opponent’s hand. Auger-Aliassime and the commentators were baffled by the Russian’s sudden decision.

Medvedev later released a statement confirming he was suffering from food poisoning.

Medvedev has been having a disappointing season so far – he went 1-1 at the Australian Open and 1-1 again in Rotterdam. But he started to turn things around in Doha, winning back-to-back matches for the first time in 2025.

The world No. 6 beat reigning champion Karen Khachanov in his opening match and, on Wednesday, destroyed Nuno Borges for the loss of just three games.

But there was a disappointing end to his Qatar Open campaign on Thursday, as the former champion retired suddenly. Auger-Aliassime reeled off four games in a row to take the opening set 6-3 and Medvedev suddenly threw the towel in.

There were no huge signs that Medvedev was struggling and the Canadian was unaware that his opponent was about to retire. He sat on his bench as usual for the end-of-set changeover.

But Medvedev didn’t go to his bench. He marched straight up to umpire Mohamed Lahyani and could be seen in conversation with the official.

Auger-Aliassime appeared confused before turning to his box and struggling. Medvedev then turned away and packed his bags as Lahyani announced his retirement.

“Ladies and gentlemen, due to illness, Mr. Medvedev cannot continue. Auger-Aliassime wins by 6-3, retirement,” the chair umpire said.

“I didn’t notice anything,” commentator Arvind Palmer remarked, while Lee Goodall said his retirement had “taken us all by surprise.”

Palmer added: “I don’t think they even shook hands, did they?” And Goodall replied: “Scratching my head here. Did not see that coming. Like you say, I don’t think there was even a handshake, was there? Just put the racket away and off he went.”

It’s the second time this week that Auger-Aliassime has benefitted from a retirement. The world No. 23 got a walkover into the quarter-final when Hamad Medjedovic pulled out of the tournament after injuring himself during his opening win against Stefanos Tsitsipas.

Auger-Aliassime will now face fifth seed Andrey Rublev for a spot in the final. The world No. 23 later addressed Medvedev’s retirement, explaining that the Russian didn’t want to shake hands at risk of spreading his illness.

“I didn’t notice. I didn’t know. I guess he was hiding it well because it was impossible for me to know that he was not feeling great,” he said.

“I think it was something to do with illness, which, you know, that’s why I think he didn’t, well he said on the court he didn’t want to shake my hand or the umpire’s hand in case of a virus, so I understand that.”

In a statement, Medvedev confirmed he had food poisoning. “Unfortunately I had food poisoning. Very disappointed to end my run here in Doha like this as I feel like I was playing well. I look forward to coming back next year,” he said.