Gilles Simon’s counterpunching wore down former US Open champion Juan Martin del Potro Sunday at Flushing Meadows, as the No. 12 seed outplayed the 2009 titlist 4-6, 7-6(5), 6-2, 7-6(3) in a grueling third-round match on Louis Armstrong Stadium. The 26-year-old whacked 11 more winners than del Potro, while hitting 29 fewer unforced errors to prevail in three hours and 57 minutes, reaching the round of 16 in New York for the first time in his sixth appearance.

"I was break up, 3-2 [in the fourth set], and then I started to play a little bit shaky. Was hitting harder and harder every time," said Simon. "Finally I started to be tired and it was really hard to play at the end of the match. It was very good to finish in four sets."

Both players started well, holding comfortably in their first four service games, playing clean, safe tennis. Serving at 4-4, Simon fell behind 0-40, and though he saved the first three break points he faced, the 18th-seeded Argentine capitalized on his fourth chance, charging the net to cause Simon to hit a cross-court backhand pass wide. He then closed out the set with a routine service game.

Often a slow starter, Simon’s level of play picked up in the second set while del Potro’s took a dip in form. Each player failed to convert two break point opportunities and the set was eventually decided in a tie-break. Trailing 5-3, del Potro brought the Frenchman forward and struck a down-the-line-forehand pass to get the tie-break back on serve. He held on his first service point to even it at 5-5, but Simon took advantage of a short groundstroke, ripping an inside-out forehand winner to move ahead 6-5. Though he hit a 72 mph second serve on set point, Simon squared the match at one-set all after del Potro committed his 23rd unforced error of the set.

Simon grabbed the momentum in the fifth game of the third set after del Potro played a poor game on serve, committing three unforced errors. Simon consolidated the break when his 22-year-old opponent netted a backhand, and eventually ran away with the rest of the set, as the combination of his defense, consistent play and ability to turn up the heat when needed frustrated the Argentine.

Down two sets to one, del Potro regrouped in his opening service game and worked to turn the tide, but Simon kept pressing and broke in the fifth game after del Potro missed yet another backhand. Del Potro however, stayed patient and after missing out on two break-point opportunities, he unloaded on a short Simon forehand with a penetrating 96 mph forehand winner to break back.

From there, the two went toe-to-toe for the duration of the match, and it was del Potro who had a chance to force a deciding set in the ninth game, jumping out to a 0-40 lead with two convincing forehand winners to give himself three set points. Simon served and volleyed for the first time to save the first break point and played fearlessly the next two points to get the game to deuce. Two timely first serves were unreturned by del Potro and the set was even at 5-5. "I knew I had to be a little bit more aggressive," assessed Simon. "That's what I tried to do. I think I played a good serve and volley. Then I hit a winner also, then a good first serve. I managed to do it. It was a very good idea." 

Two holds of serve pushed the fourth set into a tie-break and Simon opened a 3-0 lead before squandering three straight points. Unfortunately for del Potro, he misfired a forehand on the next point to give the mini-break back -- and Simon never looked back. The Frenchman set up three match points with a deep return and closed out the hard-fought victory with a well-placed, out-wide serve.

"He's a fighter, It's very hard make a winner playing against Simon," said del Potro. "I tried until the end, but I played [at a] lower level in the tie-breaks. He took the chance and he closed the match."

Simon avenged his 2008 third-round loss to del Potro at the Open, when the Argentine prevailed in a five-set clash, as well as a straight sets loss in the third round of Wimbledon this season. In the fourth round, Simon will take on the winner of an All-American battle featuring 28th-seeded John Isner and Alex Bogomolov Jr.

• Gilles Simon Bio
• Juan Martin Del Potro Bio