-- Matching Andy Roddick ace for ace for the better part of five sets, Joachim Johansson of Sweden was just looking for a service break late in the final set Thursday night. When it came -- after he had already squandered two match points at 5-4 -- it sent Johansson to the U.S. Open semifinals and Roddick, the No. 2 seed here, home to ponder missed opportunities.

Roddick, the defending champion, hit 58 winners and just 22 unforced errors, yet his final backhand of the night was beyond the baseline, securing a 6-4, 6-4, 3-6, 2-6, 6-4 win for Johansson, the No. 28 seed. The match lasted 2 hours 55 minutes. Roddick converted just 3 of 15 break chances; Johansson converted 3 of 5.

"Yeah, that's the stat. You don't really need to analyze the match any further than break points had and break points converted," Roddick said. "That's pretty much the whole match, you know."

Johansson advanced to meet No. 4 seed Lleyton Hewitt in the semifinals Saturday. Hewitt beat Tommy Haas, 6-2, 6-2, 6-2, in an earlier quarterfinal.

No. 1 Roger Federer and No. 5 Tim Henman make up the other members of the Open's final four after both won matches that had been postponed from Wednesday night because of rain. Federer took out Andre Agassi, 6-3, 2-6, 7-5, 3-6, 6-3, and Henman finished off No. 22 Dominik Hrbaty, 6-1, 7-5, 5-7, 6-2.

With Roddick and Agassi losing in the quarterfinals, the men's U.S. Open semifinal will be played without an American for the first time since 1986.

Rain also had an affect on Roddick and Johansson's match, with a delay that came 19 minutes into the match -- though after Johansson's first break -- and stopped it for about an hour.

Johansson came out of the stoppage firing rocket serves of up to 141 mph, matching his opponent's 34 aces with 30 of his own and causing Roddick to drop his only sets of the tournament. The 23-year-old Swede, who has won just one title in his career, had been averaging 19 aces per match in the tournament, but stormed past that number in just the third set on Thursday.

Playing strong tennis throughout the first two sets, Johansson jumped on Roddick early, taking advantage of the only two break points he faced in those sets. Roddick, meantime, missed on all seven of the break chances he had in the first and second sets. Continuing his futility throughout the match, he failed on the two opportunities he had in the final set as well.

"I played well on the 50 break points he had," Johansson said, with a slight exaggeration. "I think someone told me he won like 150 points and I won like 120 points. That means I won the right points. I don't know how, but it was very good for me."

But Roddick also showed the form that enabled him to take last year's Open. From late in the second set until the beginning of the fourth set, Roddick won 29 straight points on his serve. Hitting 24 winners and just three unforced errors in the third and fourth, Roddick recovered to get back in a match that had been quickly slipping through his fingers.

In the end, however, Johansson simply came up bigger in the key moments.

"I lost a couple of heartbreakers in Slams this year," Roddick said. "But, you know, the losses like this, they make me hungrier."

The biggest match of the afternoon session was a wind-blown continuation of the Federer-Agassi battle that was suspended by rain Wednesday night.

By the time they took the court Thursday, gusts of wind were wreaking havoc on groundstrokes and serves, making the U.S. Open quarterfinal as much about resourcefulness as fitness.

In the end, it was the top-seeded Federer who showed more of both, outlasting the sixth-seeded Agassi, 6-3, 2-6, 7-5, 3-6, 6-3, to earn a berth in the semifinals against Henman.

Both Agassi and Federer had trouble adjusting to the wind, which gusted up to 40 mph at times.

"We couldn't play our games," Federer said. "Usually we are guys who look for the winner, you know, play aggressive. But we could not play this way, you know. So it did feel like two different matches."

The wind forced players to completely alter their strategies depending on their side of the court. The conditions clearly affected Federer in the fourth set when he double-faulted three times in the eighth game, eventually leading to a break for Agassi.

"This is as bad as it gets," Agassi said. "I mean, I think anything sort of more than this, there would have to be some serious consideration into postponing matches. I mean, at some point, if chairs are starting to blow over, that's a problem."

Federer's victory continues his quest to win three Grand Slams in the same year -- he has already taken the Australian Open and Wimbledon -- for the first time since Mats Wilander in 1988. But standing in his way will be Britain's Henman. Henman had been trailing Hrbaty 4-5 in the third set on Wednesday night when rain suspended their match.

Despite facing the same gusts of wind that disturbed Agassi and Federer, Hewitt swept past Haas, continuing the strong play that has enabled him to win his last two tournaments leading up to the Open.

Hewitt still has yet to drop a set in Flushing Meadows and has given up an average of just eight games per match thus far.

Andy Roddick bemoans his missed chances (3 of 15 on break points) in a five-set loss to Sweden's Joachim Johansson.