Joachim Johansson held off a dramatic fightback from defending champion Andy Roddick to reach the semi-finals of the US Open on Thursday night.
The Swede will meet Lleyton Hewitt in the last four after his 6-4 6-4 3-6 2-6 6-4 victory.
Johansson looked to have let his chance slip as Roddick hit back from two sets down with some stunning serving.
But in a tense final set, he saved a break point before a Roddick error gave him victory on the third match point.
"Let's give him credit, the guy serves out of a tree," said Roddick afterwards.
"I had a good look at his serve in the fifth set but I just played a bad game.
"I had a bunch of break points and only converted a couple and he had a few and converted almost all of them."
Roddick seemed surprised by Johansson's power in the opening stages as the 28th seed took control with big serves and fierce forehands.
Second seed Roddick double-faulted on break point in the fifth game to let the first set slip and, after twice failing to convert from 0-40, was soon two sets down.
But with his grip on the title apparently weakening, the world number two dug deep to find his most devastating form.
He did not lose a point on serve in racing through the third set and, with the pressure mounting on Johansson, Roddick broke twice in the fourth to level the match.
The final set was a desperately close affair with both players sending down a barrage of aces, and Johansson saved a break point with the score at 4-4.
That blow clearly affected Roddick, who put in two double-faults as Johansson moved to 0-40 and three match points.
Two big serves suggested Roddick might recover again but on match point number three he ended a lengthy rally with a wayward backhand, and his reign as US Open champion was over.
"I've had a couple of heartbreakers in slams this year," said Roddick, who lost to Roger Federer in the Wimbledon final.
"I just have to step up and win those. I'm not happy but losses like this make me hungrier."
Johansson said: "I got a good start in the first two sets, went down a little in the middle, and then hung in there in the fifth so it was good for me.
"It was pretty windy here but I made the big shots.
"I won my first title in Memphis this year, which was good, but I think this is probably a little bit bigger."
The Swede must now prepare for his first Grand Slam semi-final on Saturday, and it will be against former champion Hewitt - the brother of Johansson's girlfriend Jaslyn.