NEW YORK - His strokes awry, his emotions laid bare for all to see, Roger Federer figured out a way to stay in the U.S. Open.

Federer found himself locked in a five-set struggle against the sort of player the world is accustomed to seeing him dismiss with ease, and it was only down the stretch that the four-time defending champion at Flushing Meadows looked the part.

Avoiding as big an upset as tennis has seen in a while, Federer came back to beat 23rd-seeded Igor Andreev of Russia 6-7 (5), 7-6 (5), 6-3, 3-6, 6-3 Tuesday night to reach the quarterfinals at the year's last Grand Slam tournament.

“Being down a set, and a tiebreak in the second set, obviously, you know, there's danger written all over that situation,” Federer said. “You just hope that it's going to turn your way. It did.”

When he finished the match with a forehand winner, Federer shook his fists violently and yelled, then flashed a grin toward his girlfriend and others in his guest box.

Hard to recall the last time this guy was so pleased by a mere fourth-round victory. Federer is, after all, a man who owns 12 Grand Slam titles, two shy of Pete Sampras' career mark. A man who has won 31 consecutive matches at the U.S. Open. A man who is trying to extend his record streak of 17 straight appearances in major semifinals.

And yet Federer couldn't stop smiling at the end of the 3.5-hour test, in part because, he explained, he found it fun to be pushed into a fifth set.

“I don't give myself the opportunity that much, you know, because I always win easily,” he said. “I was just really pleased with my fighting spirit.”

Novak Djokovic felt the same way about his five-setter on the same court earlier Tuesday. When Djokovic's 4-6, 6-2, 6-3, 5-7, 6-3 victory over No. 15 Tommy Robredo of Spain was over, the 2007