Elena Dementieva outlasted second seed Lindsay Davenport 6-1 3-6 7-6 (8-6) to reach the last four of the US Open.
The sixth seed steamrollered her way through the opener, breaking the American world number one four times.
But Dementieva unravelled in the second as Davenport stamped her authority on the match with a double break to level.
Both players battled it out in a game of cat and mouse in the third but Dementieva clinched the tie-break to set up a semi-final with Mary Pierce.
Even though Dementieva lost her serve once in the opening set that was a mere blip in an otherwise flawless display.
She controlled her characteristically wayward serve and broke Davenport four times, wrapping up the set in 27 minutes.
But it was the 1998 champion who dominated the second, immediately breaking the Russian as she stepped up her aggressive play.
Dementieva's sense of poise seemed to have deserted her as she double-faulted to hand the American a second break.
The sixth seed recovered to break straight back at 4-2 but lost her next service game thanks to some rash forehands to hand Davenport the set.
The match cranked up in the final set with both players staving off break-points in lengthy opening games.
Dementieva made the breakthrough in the seventh game but the 29-year-old American showed her steel by breaking straight back with ease.
The Russian, who finished as runner-up in 2004, broke again at 6-5 only to be undone by her 12th double-fault to see Davenport break again and force the tie-break.
Second seed Davenport clawed her way back from 5-2 down with some stunning groundstrokes but could not convert her match-point chance.
And she paid the price as Dementieva fired down a backhand winner to reach her third semi-finals at Flushing Meadows.
Afterwards, she said she was already thinking about the prospect of repeating last year's achievement of reaching the final, where she lost to compatriot Svetlana Kuznetsova.
"I feel this is a lucky place for me and I am just so excited right now," the Muscovite said.
"After last year I've been dreaming about Saturday night every single day so who knows?"
Davenport admitted she had not been at her best, saying: "I was making errors on balls I didn't need to make errors on.
"I was never in control of points. I just didn't play the type of tennis I would have preferred to play."