John Isner has booked his place in the second round of the US Open thanks to a 7-6 6-2 7-6 victory over American rival Marcos Giron.

The unfancied Giron was impressive early on as he matched his rival's dominant services games, before surviving a couple of scares late in the opener to force a tie-break.

Despite seeing his opponent take a 3-1 lead, Isner was strong enough to fight back and take the first set with a 7-5 success in the tie-break.

The second set proved to be far more comfortable for Isner as he was gifted the advantage when Giron lost his serve in the opening game. Giron was unable to produce a response to the setback, and Isner went on to secure one more break of serve before claiming a 2-0 lead.

Both players were back to their best on serve in the third set, but Isner's experience allowed him to battle through in the final tie-break, with the 13th seed storming to a 7-2 success to ensure he remained in the final major of the year.