John Isner has progressed into the third round of the US Open with a straight-sets win over Jan-Lennard Struff this evening.

Nothing could separate the duo in a thrilling first-set encounter, with both players deadlocked on six games apiece en route to the tie-break.

Isner looked poised to win the tie-break after taking a 6-3 lead to hold three set points. Struff fought back to 6-5, but the American held serve to take a one-set advantage.

The second set looked to be going the same way, with the pair tied on 4-4. However, Isner produced a crucial break - the first of the match - to move 5-4 ahead, before holding his own serve to move within one set of victory.

Struff's resistance further waned in the third set, with Isner wrapping up the win courtesy of a 6-2 scoreline to advance into the third round.