Americans James Blake and Sam Querrey crashed to defeats to leave Frenchman Gilles Simon and Russian Dmitry Tursunov to contest the final of the Indianapolis Tennis Championships.
Second-seeded Simon stayed steady as fourth seed Querrey suffered a physical meltdown in the final set to lose 6-3 4-6 6-4.
The notably fragile Blake opened the door to defending champion Tursunov, returning after a second-set rain break with nothing left on his serve and paying the price 4-6 6-3 6-4.
"I don't know what happened," said the distressed top seed, who had been counting on the hardcourt summer to rescue his game after Roland Garros and Wimbledon second-round defeats.
"I didn't have a first serve when I needed it. It's one of those things that can happen unfortunately," said Blake, who clawed back a break in the final set but lost the match as the Russian struck again a game later.
Third seed Tursunov admits he remains an unlikely finalist as he defends a title for the first time.
"I'm confident that I can play well," he said of his first meeting with the 25th-ranked Simon.
"If I play well I have my chances - as long as he doesn't blow me off the court."
Tursunov last played a final in Sydney at the start of the year, an event he won for his fourth career trophy. He improved to 23-14 this season.
Simon said he got a lift as Querrey began to fade badly.
"I kept fighting, especially when I could seem him leaning on his racquet after points in the third set," said Simon, playing in his first American semi-final.
"I could tell he was tired and that kept me fighting."
Simon, who won a third career ATP title in Casablanca in May, improved his season record to 25-16 as he became the first French player since Olivier Delaitre in 1994 to challenge for the Indy title.
The match was a fitness disaster for Querrey, who looked like making an early exit while trailing a set and 4-2.
The Californian whose huge serve produced a mere three aces, somehow rallied in the second set, recovering from a break in the sixth game with a break-back in the seventh for 3-4 as Simon donated a pair of double faults.
He squared the contest at a set each, but then began to fade badly in the third.
Querrey saved three break points to hold for 4-4 in the third, then forced Simon to save five a game later.
But the fitter Frenchman broke in the final game to lift the win.
