Spadea will face defending champion Fabrice Santoro on Saturday, after 1989 French Open champion Michael Chang is inducted into the Hall of Fame during afternoon ceremonies. Santoro defeated Ivan Navarro, 6-3, 7-6 (4).
Spadea's win over Peya earned him his first trip to a semifinal since Delray Beach last year.
"I played well at the right times,'' Spadea said. "I think I'm playing well enough to beat anybody in this tournament.''
The 33-year-old Spadea was broken in the first set to fall behind 4-5, but he broke back in the next game to eventually force the tiebreaker.
In the tiebreaker, Spadea won the first of three consecutive points by converting an overhead smash. Peya was then barely able to get a racket on Spadea's serve on the next point, tipping the ball short.
Spadea took the tiebreaker after charging the net, forcing Peya to make a desperate forehand bid that sailed wide and closed the opening set.
In the second set, Peya broke Spadea in the third game en route to a 4-1 lead. But Spadea rallied to tie the set at 5-all and took the lead when Peya doubled faulted on consecutive points before hitting a forehand return into the net in the game's final three points.
Spadea, of Boca Raton, Fla., closed out the match with a backhand slice at the net. His only career title was at Scottsdale in 2004.
Peya said he didn't capitalize on the few opportunities Spadea gave him.
"I felt like (Spadea) didn't give me too many easy chances on the important (points), and I didn't make many,'' he said.
The 35-year-old Santoro is the oldest champion in the tourney's 32-year history. A first or second seed has not captured the title in the past 18 years.
Santoro, the second seed, scored six of the last seven points in the tiebreaker to close the match. The six-time tournament champion noted he and Spadea will bring plenty of experience to their match.
"All together we'll be almost 70 (years old) on the court,'' Santoro joked. "I've known Vince for many years. He's had a great career. I saw his match today. He's playing very well.''
Prakash Amritraj plays seventh-seeded Frank Dancevic, Canada's top player, in the other semifinal Saturday.
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