At 19, Jack Sock could be the next great hope for American men's tennis.


At 30, Mardy Fish is already part of the old guard.


Both players won their second-round matches Thursday at the U.S. Open, keeping alive the hope that at least one American could make a deep run here.


Sock, who was born in Nebraska and lives in Kansas City, routed Italian Flavio Cipolla, 6-2, 6-2, 6-4 on Court 17, punctuating the match with an exaggerated fist pump that delighted the crowd.


Shortly thereafter, the No. 23-seeded Fish completed a comeback from two sets down to beat former world No. 3 Nikolay Davydenko of Russia, 4-6, 6-7 (4), 6-2, 6-1, 6-2 in Arthur Ashe Stadium. It was the 10th comeback from 0-2 down in this men's tournament, a new record.


"You want to play so well out there," Fish, who is in the same quarter of the draw as No. 1 seed Roger Federer, said in his on-court interview. "As an American you just love playing on this court. You're getting such good crowd support. It's hard to explain so you come out a little nervous, a little flat and hopefully that won't happen next time."

No American has won the U.S. Open since Andy Roddick in 2003. In fact, that's the last time an American man won any Grand Slam singles tournament.

"I think we definitely have a good group of guys coming up, a good group of guys working hard trying to get there," Sock said after his first-round match. "We have a group of guys already there — John [Isner], Mardy.

"Until the results are there, until the rankings and everything is there, [there's] not a different answer to give [about the future of American tennis]."

Fellow Americans Sam Querrey, the No. 27 seed, and James Blake also won Thursday.

On Friday, Americans Isner, Roddick, Ryan Harrison, Brian Baker and Dennis Novikov all play.

While the 6-foot-9 Isner, the No. 9 seed, and the big-serving Roddick probably have the best chances to do damage this year, Sock and Harrison are the faces of the future.

Sock meets No. 11 Nicolas Almagro of Spain next, while Harrison, 20, faces 2009 champ Juan Martin del Potro on Friday.

"Whoever I'm playing, I'm going to give it my all and try to win," said Sock, a former USTA Boys' 18 champion who won a round in singles last year and also captured the mixed doubles title with fellow American Melanie Oudin. "Definitely winning last year gave me more confidence to try to advance in the draw as far as I can. I'm going to try to use that and go as far as I can this year."

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