Second seed Fernando Verdasco defeated fellow marathon man Milos Raonic to reach the Estoril Open final Saturday after his exhausted opponent retired injured after dropping the first set of their semi final.
The 27th-ranked Canadian breakthrough player was reportedly suffering with a back injury.
Raonic had lost the first set after 41 minutes - saving a set point - then walked to the umpire's chair to shake hands and retire 4-6.
Spain's Verdasco will Sunday face off against Argentine eighth seed Juan Martin del Potro, who beat good friend Pablo Cuevas of Uruguay 6-2, 7-6 (8/6).
The 46th-ranked Del Potro, who once stood inside the top five before wrist surgery ended his 2010 season more than a year ago, is aiming for his second title of the season.
Number 15 Verdasco and Raonic both had to play quarter finals stretching over two days due to atrocious weather on the Portuguese coast near Lisbon. Storms moved in Friday after a week of brilliant sunshine.
Verdasco, fighting to return to the top 10, overcame South African seventh seed Kevin Anderson 6-7 (2/7), 6-2, 6-3 while Raonic completed a win over fourth-seeded Frenchman Gilles Simon, 7-6 (7/4), 4-6, 6-3 on Saturday.
Raonic beat Verdasco in two previous meetings this season, in the San Jose final - the first title for the Canadian - and a week later in the Memphis first round.
Raonic won with seven aces and five breaks of the Simon serve, taking two-and-a-half hours to go through in his first ATP season on clay.
"Stopping twice was hard for me," said Simon, "The only advantage I had in the match was my ability to go nonstop for three hours."
"Instead, we'd play an hour and then go off for rain. I may have lost but I'm confident in my tennis."
While Del Potro and Cuevas finished their quarter finals on schedule on Friday, the weather caught them out in the semi final with an interruption.
But Del Potro did not let the pause disturb as he lifted his 2011 record to 24-6 including a title on cement in February at Delray Beach, the eighth of his career.
Saturday's women's final at the Estadio Nacional was also interrupted by the rain.
However, Spain's Anabel Medina Garrigues came back out after the break to round off her victory against German Kristina Barrois 6-1, 6-2 in 75 minutes with six breaks of her 29-year-old opponent's serve.
"I played very aggressively and hit it high and deep, Kristina couldn't play her game," said the winner.
Medina Garrigues was playing her first WTA final of the year, but 16th of her career and first since 2009.
The Spaniard now holds nine clay titles, level with leader Venus Williams among active players in that category.