Top seed Roger Federer dropped his first set of the tournament before rebounding in style to tame towering American wildcard John Isner 6-7 6-2 6-4 6-2 in the third round of the US Open.
The three-times defending champion was edged out in a tie-break in the first set but then roared back to clinch victory in two hours 15 minutes and reach the last 16.
'It's so hard to play against players like him, you just hope he's not going to keep serving aces,' Federer told the crowd.
'It was unbelievable how he served in the first set but I started to get a read of it a bit in the second and third sets especially.'
Isner, 22, playing in his first US Open and his fifth Tour event, held his own with the world number one in the first set and sent the crowd wild when he snatched the tie-break 7-4.
But Federer stepped up a gear in the second and third sets, losing just five points on serve in the process, and then eased through the fourth to set up a clash with Spaniard Feliciano Lopez.
Isner said it had been a pleasure to play the top seed.
'When I looked at the draw, saw that if I won a couple of matches I was going to play this guy,' he said.
'I won a couple of matches and got to play him on Arthur Ashe, and it was such an honour.'
'It's nice to see it but at the same time it makes you want it again,' he said.
American veteran and sixth seed James Blake moved on, but not before playing two hours and 39 minutes of tennis against unseeded Austrian Stefan Koubek.
After the two sparred rather evenly for the first three sets, Blake turned it into high gear in the 25-minute fourth set to clinch the 6-3 3-6 7-6 (5) 6-1 victory.
Blake claimed the first set after falling behind 3-1, but the American committed 16 unforced errors in the second set to allow his opponent to draw even.
Koubek broke Blake in the pivotal third frame to go ahead 5-4, but the local New York product broke right back, rattling off four straight points. Both men then held serve to set the stage for a tiebreak that Blake squeaked out of. The set took an hour and four minutes to conclude.
On a day that saw the second and seventh seed fall on the women's side, Blake avoided a major letdown.
Number 19 Andy Murray was the day's only upset victim in the men's draw. The 20-year old Brit was outclassed by Korean Hyung-Taik Lee. The 31-year old Korean reached the Round of 16 for the second time in his career by knocking off Murray 6-3 6-3 2-6 7-5.
The triumph was Lee's third over a Top 20 opponent in 12 tries thus far this season.
The second victory came his last time out when he sent home number 14 seed Guillermo Canas.
Roddick had a much easier time than his countryman Blake.
The fifth seed and 2003 champion, Roddick remained perfect all-time against Swede Thomas Johansson with a 6-3 6-2 6-0 romp.
Roddick, who improved to 5-0 lifetime against Johansson with his rout at Arthur Ashe Stadium, may face the 2002 Australian Open champion again in three weeks when the United States visits Sweden in Gothenburg for the Davis Cup semi-finals.
Roddick will next play number nine Tomas Berdych of the Czech Republic, a 7-6 (7-2) 6-1 7-6 (7-3) winner over Spaniard Fernando Verdasco, and could face Federer in the quarter-finals.
Earlier Saturday, fourth-seeded Russian Nikolay Davydenko became the first man to reach the fourth round at the year's final major with a 7-5 6-0 7-5 victory over 28th-seeded Spaniard Nicolas Almagro at Armstrong Stadium.
Davydenko, who has dropped a total of 21 games through three rounds, awaits Korean Hyung-Taik Lee in the round of 16.
A semi-finalist here in 2006, Davydenko had retired with a leg injury in his only previous meeting with Almagro, in Rome last year.
