If you are looking for someone who has the potential to shock a higher seed in the field at the U.S. Open, look no further than Gael Monfils. On Wednesday, the native of France served his way to the quarterfinals of the Winston-Salem Open, defeating Tommy Robredo 7-6, 4-6, 6-2.

Monfils was at the top of his game before a knee injury sidelined him. He watched his ranking nose dive while he rehabbed and is working his way back during his comeback. He is clearly much more dangerous than his world ranking, which is 49.

In Monfils, you have a competitor with a lot of weapons at his disposal. On Wednesday, his serve was exceptional. Monfils placed 77 percent of his first serves in, winning 78 percent of those points. He served 5 aces in the match.

Robredo of Spain entered the match ranked 23rd in the World and has had some impressive wins this summer, mostly on clay. He did defeat Stan Wawrinka  in Cincinnati on the hard courts, fresh off of winning the ATP Umag title on clay.

Monfils and Robredo last clashed in Roland Garros at the French Open where Robredo emerged victorious in 5 sets.

On Wednesday, after winning a first set tiebreak, Robredo bounced back to take the second. In the third, it was all Monfils, dominating play on his serve.

He advances to face Fernando Verdasco in the quarters on Thursday. Monfils has won both meetings between the two.