It's been quite a summer for 18-year-old Noah Rubin of Rockville Centre. The Wake Forest-bound freshman won the Wimbledon Juniors title and followed that up with a championship at the USTA 18s title in Kalamazoo, Mich. While the former may have had more international cachet, particularly to casual tennis fans, it was the latter that earned Rubin a wild card entry into the main draw into the US Open.

In just his second pro tournament (he accepted a Wild Card into Winston-Salem last week), Rubin drew Argentina's Federico Delbonis, a 23-year-old who came into the Open ranked No. 66. With a packed Court 13 crowd solidly behind him, Rubin was strong early before falling in straight sets, 6-4, 6-3, 6-0.

"I learned that I can definitely compete with these guys at the best level," he said. "If I stayed on serve throughout the whole first set, who knows what would have happened. If I kept the momentum going, I probably would have had more opportunities but just didn't capitalize on it."

The big crowd, opening match jitters and Delbonis' lefty stroke put Rubin in an early 3-0 hole. Though Rubin got one of the break points back and closed to 2-3, his Argentine opponent's experience proved critical.

In the second set, Delbonis broke in the seventh game for a 4-3 lead and wouldn't lose a game the rest of the way.

Rubin has played here in Flushing Meadows before, competing in the US Open juniors. But the big stage of the main draw was a different experience.

"It's completely different sports," he added. "The pros, they are doing it for a living. Been out here for so long. The experience is a different level. Fitness is at a different level. So it's definitely something to get used to."

Sam Querry, another American who rose through the ranks of juniors, had a bit of advice for Rubin.

"My advice to guys is to try to put your head down and battle through futures and champions," he said. "I think he has a good game to move up the ranks. I know he's going to college for a year, so try to dominate the next level and get in the Tour events as quick as he can."

In all, Rubin, who also earned a wild card into the main doubles draw with partner and friend Stefan Kozlov and will play on Wednesday, is using his first Slam as a learning experience.

"I'm just trying to show everybody I can compete at this level and try to make people proud of me," he explained. "I'm just getting used to the atmosphere, getting used to being out there with the best players in the world.

"It's nice to know I belong here and I'm not just taking a vacation here just seeing what it's like and going back. I deserve to be here and work to stay here."