Andre Agassi and Andy Roddick, the top two seeds, both crashed out of the $600,000 Washington Classic in the semi-finals on Saturday.
World number one Agassi was felled by fourth-seeded Chilean Fernando Gonzalez 3-6, 6-4, 7-6 in a match peppered with misplaced shots on both sides of the net, while second seed Roddick went out 1-6, 6-3, 7-6 to Britain's Tim Henman, the 10th seed.
In the third set, Agassi, 33, double-faulted to give his opponent a break of serve at 4-2. But Gonzalez double-faulted at match point, allowing the American to break back to level at 5-5. A backhand winner then gave Gonzalez, 23, the decisive break of serve at 6-5 in the tiebreak.
Agassi told reporters the Chilean unsettled him with high-risk, low-percentage strokes, particularly drop shots.
"I'd hate to go to sleep at night counting on that shot but, that said, he played them really well," said the top seed.
"He takes big cuts at the ball and goes through stages where he makes a lot of errors and then goes through stages where he puts it all together."
Gonzalez said his risky moves paid off. "Sometimes you have to change, you have to make him play where he doesn't like to play," Gonzalez said.
Asked if he ever changed his playing style, he said: "Sometimes, when I lose. But normally I try to go for it."
Earlier, Roddick overpowered Henman in the first set but the Briton seized control early in the second, breaking serve in the fourth game to the frustration of his 20-year-old opponent, who hit a ball into the top rows of the open-air stadium.
RIVAL RATTLED
His rival rattled, and momentum on his side, Henman held serve in the third set to force a tiebreak, which he won 7-1 thanks to a string of errors by the American, one of the favourites for the U.S. Open later this month.
Saturday's semi-final was the first meeting between the two players.
Henman said after his second set break, he focused on keeping his serve consistent and using a variety of shots to disturb the hard-hitting Roddick's rhythm.
"I wasn't overly concerned about his service games. I very much thought that my focus and attention was going to be on my own serve, and if I got an opportunity on his serve, great," Henman told reporters.
"From pretty early on in the third set, I felt like we were looking at a tiebreak. And then once I got there I did feel pretty relaxed.
"I didn't really feel like I had anything to lose at that stage," he said.
Henman, who had shoulder surgery in November, has not won a singles title since January 2002 in Adelaide. The 28-year-old had not reached a tournament final since the Queen's Club event in London in June last year.
Gonzalez has won two of his last three meetings with Henman.
Roddick, who won a hardcourt tournament in Indianapolis last week, defaulted from a doubles semi-final he was scheduled to play immediately after his match against Henman.
"I have to look out for my first priority, which is singles. I have two huge tournaments coming up in the next two weeks, followed by the (U.S.) Open," Roddick said.
"It's a decision that I might have not been professional enough to make a few years ago."
