World No.8 Felix Auger-Aliassime's Australian Open was cut brutally short when he was forced to retire at the beginning of the fourth set of his first-round match. Seeded seventh this week, the Canadian ended 2025 on a high and hoped to carry that momentum into 2026.

After taking the first set over Nuno Borges on the John Cain Arena on Monday morning, Auger-Aliassime lost the next two sets and could barely move at the end of the third. He called the physio and received some treatment ahead of the fourth set before attempting to play on.

But Auger-Aliassime managed only one more point before throwing in the towel and walking to the net to shake hands with Borges. "Well, this is such a sad moment for Felix Auger-Aliassime, semi-finalist at the last Grand Slam at the US Open, he's out, spectacularly, by retirement," commentator David Basheer said.

Colin Fleming replied: "Just so sad to see, congratulations Nuno Borges, such a tough player, but not the way he would have wanted to win either. Auger-Aliassime was looking so sharp and moving so well in the early stages, but his body has unfortunately let him down here in John Cain Arena, and it's Borges who advances to round two.

"Just feel for him and his team. It's horrible, you never want to see a player struggling with injury. I have to say, the way the third set ended, it didn't look like there was any way it could continue. He couldn't compete, couldn't move."

Portuguese world No.46 Borges advances to the second round 3-6 6-4 6-4 ret. Following Auger-Aliassime's retirement, he said: "Honestly, it's not that difficult for me, I just feel for him. I know how it feels to struggle physically, and it is part of tennis, it's a rly long schedule, it's really hard to stay on top of our game, and physically it is very demanding, so I can totally understand. I hope he gets better quick and back to his best level.

"Obviously, it's a great win for me, either way. I thought I competed well, maybe if he was 100 per cent, it would have been a different score, obviously. But I'm really happy to push through this one, get another opportunity on Wednesday."

Auger-Aliassime was one of the in-form players at the end of 2025. After reaching the US Open semi-finals, he won the title in Brussels, finished runner-up at the Paris Masters, and qualified for the ATP Finals, where he made it to the semis. He reached a career-high ranking of No. 5 in November and would have been targeting a deep run in Melbourne.

The world No. 8 later revealed that he had been suffering from cramps - something that took him by surprise, especially given how early it came in the tournament. "I'm okay, but I just started cramping at the start of the third set. Yeah, it became very difficult to be competitive at this level. I tried for a set, but yeah, wasn't possible today," he explained.

"I don't have all the answers now. I'm trying to be very professional at everything I do, prepare well. I love this sport, and I love to play. So I try to do everything I can in my control to get ready.

"Obviously it hurts even more, because you know, if I was self-aware and I was, like, well, I wasn't really ready or I wasn't doing everything, then you have to be honest with yourself. But even with being honest with myself, I'm not totally finding the reasons why this is happening. It wasn't happening in the past, so I'll have to figure it out."

Touching on his brief chat with the physio at the end of set three, Auger-Aliassime added: "Yeah, like, it's not my first time. I just knew it wasn't heading in the right direction. I don't like to be on the court that way. I want to be on the court winning. I want to be on the court competing with my opponent. I don't want to be just standing there, you know, like a punching bag. So there's no point, and you know to move on."