Donald Young has come from two sets down to defeat 11th seed Gilles Simon 2-6 4-6 6-4 6-4 6-4 in the first round of the US Open at Flushing Meadows.

Young showed intent early on by breaking Simon's serve at the first time of asking in the opening set, but the Frenchman managed to respond with an instant break of his own.

Simon aimed to wrap the first set up quickly, and despite taking a further two breaks of serve, Young displayed a fighting spirit as he forced his opponent to work for the one-set lead.

It was a more even contest in the second set as games went by way of serve in the early exchanges, with Simon creating the first opportunity of a break in the eighth game.

The Frenchman, who was knocked out in the fourth round of this tournament last year, eventually managed to go a break up, which was enough to take a one-set lead on Court 17.

With a mountain to climb, Young struggled to make an early impact in the third set as Simon eased his way to a 3-0 lead, but he was able to find his feet by earning a double break before battling to win the set.

In the fourth, Simon suffered a wobble as he dropped serve three times before Young was able to edge ahead and push the contest into a deciding set.

Young went from strength to strength as he broke Simon at the first time of asking in the final set, and despite losing serve in the fifth game, the American was able to respond and eventually clinch victory.