Dylan Alcott has begun his farewell appearance at the Australian Open, with a come-from-behind performance against Dutch rival Niels Vink.
The world number one lost the first set but recovered to triumph 6-7 (1-7), 6-4, 6-2 in the quarterfinals of the quad wheelchair singles.
The 31-year-old Australian and Vink are at different ends of their respective careers but have built a friendly but competitive rivalry.
Alcott beat the 19-year-old in an emotional semifinal at the Tokyo Olympics last year, while he also won when they met in the US Open final.
The victory in New York gave Alcott the 'Golden Slam' after he won all four majors and the Olympic gold medal.
Alcott said he was in considerable discomfort during Sunday's victory.
"I was cramping, I was in trouble," he said.
"But a 19-year-old's got more energy than a 31-year-old. So I knew he wasn't going to go anywhere.
"He had a little injury at the end there, I hope he's all right."
Alcott said he knew he needed to make up for starting slowly against Vink.
"In those moments I played the big points poorly early," he said.
"I think I played the big points well in the last set and that's why I won the match."
Alcott has won seven straight quad wheelchair singles titles at the Australian Open.
He said he expected Vink to soon enjoy success at the majors.
"I said to him at the net he'll probably win 20 of these," Alcott said.
"He's very, very good. Glad I could escape one last time, put it that way."
Alcott will play another of his great rivals, British world number three Andy Lapthorne, in the semifinals.
He announced in November he would retire after the Australian Open.
