Andre Agassi won one set Friday, enough to make him a finalist at Key Biscayne for the seventh time.
The four-time champion advanced when Marcelo Rios retired because of recurrent knee tendinitis with their semifinal match tied after two sets at the Nasdaq-100 Open.
Agassi lost the first set 7-6 (9-7) and won the second 6-4. During the ensuing changeover, Rios briefly consulted with trainer Doug Spreen, then retired and shook Agassi’s hand.
“I was very surprised,” Agassi said. “The last thing you’re expecting is for the match to come to kind of an abrupt end.”
The ninth-seeded Agassi’s opponent Sunday will be No. 12 Roger Federer, who upset No. 1 Lleyton Hewitt 6-3, 6-4.
Rios said his inflamed right knee has bothered him for two months, and he was unsure whether he would even be able to take the court. The knee hurt when he pushed off to serve or run, he said, and the pain became too severe to continue.
The 699th victory of Agassi’s career was his first in three matches against Rios.
“If I wasn’t injured, there was no way he could beat me,” the Chilean said. “I was playing much better than him. But that’s the way it goes.”
On Sunday, Agassi can add to the Key Biscayne titles he won in 1990, 1995, 1996 and 2001.
Federer is in a Tennis Master Series final for the first time and has yet to lose his serve or a set in the tournament. He was nearly flawless against Hewitt, ending the Australian’s 15-match winning streak.
In the women’s final Saturday, top-seeded Jennifer Capriati plays No. 8 Serena Williams, with each bidding for her first Key Biscayne title.
