By Larry Fine
Five-time U.S. Open winner Federer dismissed Melzer 6-3 7-6 6-3, taking the second-set tiebreaker by 7-4, as he extended his record by reaching a 26th consecutive grand slam quarter-final.
Federer, 29, played with his accustomed style on Arthur Ashe center court, registering 41 winners to 23 for the Austrian as he continued his 2010 Flushing Meadows run without the loss of a set.
Waiting in the last eight for the second-seeded Swiss is fifth seed Soderling, who eliminated Federer in the quarter-finals of the French Open for his only win against him in 13 meetings.
"He's always been a dangerous player but these days he's been able to do it consistently, at the highest level," Federer said about Soderling. "So this is a tough draw for me, playing him in the quarters."
The Swiss master, who has won 45 of his last 46 U.S. Open matches, benefited from two net cord points during the tiebreaker against Melzer, the second one at 4-4 giving him the only mini-break of the decider.
"Obviously, the tiebreakers are always crucial," Federer said. "It was a tough match today, breezy. He's a tough opponent and a close friend of mine so it was never going to be easy. I'm really relieved and happy to get through."
Melzer was disappointed.
"I think I deserved the second set," said the 29-year-old left-hander. "I was the more dangerous player. I had break points. He didn't have any. You couldn't be more lucky in a tiebreaker than he was in this tiebreaker."
The Austrian, who screamed in frustration at the end of the decider, said Federer told him he was sorry about the tiebreaker when they met at the net after Federer ended it with a love game, punishing another of Jurgen's misguided drop shots for the final point.
"I haven't lost a set so obviously I'm very happy," Federer said. "I'm happy I'm finding a way to win. I'm playing the right way, playing aggressive, so it's a lot of fun out here."
(Editing by Steve Ginsburg)