Roger Federer reached the Australian Open final on Friday after Hyeon Chung retired injured, having failed to keep pace with the defending champion.
Federer was cruising 6-1 5-2 when Chung, who was unable to muster much resistance throughout Friday's semi-final, called it a day. He had been struggling with an injury to his left foot.
Last year's winner Federer will now meet sixth seed Marin Cilic - who ended the hopes of Britain's Kyle Edmund - in Sunday's final.
There was a smattering of boos but Federer had huge sympathy for his opponent. He said: "I thought the first set was kind of normal, I couldn't tell what was going on with my opponent.
"In the second set I started to feel he was getting a bit slower, fighting with the blisters. I've played with blisters in the past and it hurts a lot. At one point it's too much. It's better to stop. This feels bittersweet. I'm incredibly happy to be in the finals but not like this."
World No 58 Chung, from Korea, had enjoyed a dream campaign similar to Edmund's as he raced to the final four of the Grand Slam but he was outclassed by Federer.
The 19-time Grand Slam winner, who will now vie for a sixth title in Melbourne on Sunday, broke Chung's serve at the first attempt and took the first set before his inexperienced opponent had settled.
Federer brought up three break points to quickly move 3-1 up in the second set, by which point Chung's fate looked ominous. He called on the trainer because he was suffering from blisters at 1-4 down.
That time-out briefly rallied Chung, in just his 17th major match, to win the next game but he was soon forced to yield to Federer, who was making his 382nd Grand Slam outing.
Federer, 36, will now play his 30th Grand Slam final with Cilic, the 2014 US Open winner, as his opponent. Federer beat Cilic in last year's Wimbledon final.
His seventh appearance in the final here also sets yet another new mark.