NEW YORK -- Third-seeded Tommy Haas survived a five-set marathon at the U.S. Open on Wednesday, overcoming a controversy over his shirt and an aching right arm to wear down unseeded David Sanchez 7-6 (1), 3-6, 3-6, 6-4, 7-5.

The match stretched 3 hours, 23 minutes, and Haas had to overcome a sudden rash of double faults at the end to prevail.

Earlier, former champion Pete Sampras had an easy victory while Wimbledon finalist David Nalbandian was an upset loser.

Haas seemed headed for the exit, struggling mightily against Sanchez. Haas won a first-set tiebreak but dropped the next two before he came back for the victory. Even at the end, it was not easy. He double-faulted on two match points after having just five double faults in the match. There was one more double before Haas finished off Sanchez.

It was a long and difficult match for Haas, already struggling with tendinitis in his right arm and shoulder. When he showed up for the match wearing a sleeveless shirt, he was ordered to change into more traditional tennis garb.

Sampras, a four-time winner of this event but seeded at No. 17 and still seeking his first tournament championship in 25 months, posted a 6-1, 6-4, 6-4 victory over Albert Portas.

Sampras, who has not won a tournament since taking his record 13th Grand Slam at Wimbledon 2000, boomed serves at up to 131 mph and was never troubled by the Spanish clay-court specialist in his first match of this year's Open.

It was a promising start for Sampras, runner-up at this tournament each of the last two years and convinced that he still has at least one more major victory left in him.

"It felt really good,'' Sampras said. "I felt like I played really well. I have no complaints with the way it went. It's been a struggle this year. I've lost some confidence. But this is the U.S. Open.''

Paradorn Srichaphan won 6-1, 6-3, 6-0 over Prakash Amritraj.

Nalbandian, seeded No. 16, was defeated by unseeded Sargis Sargsian 6-1, 6-4, 6-4. No. 33 Greg Rusedski got started with a 6-1, 4-6, 7-6 (1), 6-3 victory over Alex Kim that included 19 aces.

Sargsian hit 12 aces to just one for Nalbandian and capitalized on 43 unforced errors by his 20-year-old opponent.

In Nalbandian's fifth Grand Slam, it was the first time he lost in the first round and a dramatic reversal from his success at Wimbledon, where he lost in the finals to Lleyton Hewitt. Sargsian had been a first-round loser in each of his last three appearances at the Open.