Andy Roddick upset by John Isner

The latest news of US open is the Fifth-seeded Andy Roddick was upset by John Isner, 7-6 (3), 6-3, 3-6, 5-7, 7-6 (5), on Saturday night. (Timothy A. Clary / AFP / Getty Images)

Reporting from New York - When Andy Roddick saved three match points against John Isner, he did it from the bottom of his feet. Andy Roddick rose up, lifted up and pounded out service aces.

But then there was a fourth match point, and the start of that point belonged to the 24-year-old John Isner, a 6-foot-9 former NCAA champion who has been sick with mononucleosis this summer and who was starting to cramp.

John Isner didn't serve an ace. But John Isner served big and he rushed the net to hit some volleys and stretch his long arms and dare the fifth-seeded Roddick to hit the ball past him.Andy Roddick tried, Andy Roddick couldn't and John Isner had himself the biggest upset of the U.S. Open men's tournament, 7-6 (3), 6-3, 3-6, 5-7, 7-6 (5) Saturday night.

John Isner reacts after upsetting Andy Roddick during their third round match at the US Open in Flushing on Saturday.

It took one hour and 21 minutes for Isner to win the first two sets and 1:36 for Roddick to win the next two. Isner may be the first underdog to have gathered so little support at Ashe Stadium, but the large majority of the crowd was firmly in Roddick's corner. So was momentum going into that final set.

"Any time somebody comes back from two sets, momentum is certainly on your side," Roddick said. "In the fifth set I knew I wanted to finish it before it got to the tiebreaker and kind of became a shootout."

Andy Roddick had statistical reason to fear the tiebreaker. Coming into the match, Isner had won 14 of the 15 tiebreakers he had played.

Even if, as Andy Roddick said, he had come into this tournament with a huge sense of confidence, sometimes there is nothing to be done against a large, tall guy who keeps hitting big serves and rushing the net.

John Isner missed both the French Open and Wimbledon because of his illness, and he said he felt fatigue in the fifth set against Roddick.

Next up for the former Georgia Bulldog will another physical challenge.