New York, Sep 1 (IANS) Frenchman Gilles Simon, the 26th seed, upset World No.5 and fourth seeded Spaniard David Ferrer 6-3, 3-6, 6-1, 6-3, to reach men's singles round four at the US Open here.

It was the first time for the 29-year-old Frenchman to reach US Open fourth round since 2011, reports Xinhua.

The two had met for six times before the match Sunday, and Ferrer had won five of the encounters. However, the 32-year-old veteran made as many as 52 unforced errors and lost the match.

"I feel it was one of the hardest days for me on the court because it was hot and it was so humid," said Simon about the hot and wet weather here Sunday.

"I have never sweat like this in the last ten years, I feel."

The match lasted for nearly three hours. The two players levelled until 3-3, and Simon claimed three straight games to win the first set.

The second set saw Simon leading 2-0 at the beginning, but Ferrer managed to come back, tie the score and broke to finish the set 6-3.

Ferrer didn't keep his pace in the third set, in which Simon accomplished three breaks to win 6-1. Ferrer seemed to be out of energy in the fourth and final set and was easily defeated.

"There is a lot of humidity, and it was not easy for me," said Ferrer after the match.

"I was not good with my fitness. He was better."

It is the earliest US Open exit for Ferrer since 2009.