Juan Martin Del Potro has outslugged John Isner in four sets to reach the semi-finals of the US Open after a towering battle in a sweltering Arthur Ashe Stadium.
The two big men battered each other to near exhaustion in the heat and humidity but it was the Argentine third seed who proved the stronger to prevail 6-7 (5-7) 6-3 7-6 (7-4) 6-2 in three-and-a-half hours.
With the mercury hitting 35C and humidity at about 50 per cent, the US Tennis Association invoked its new extreme heat policy, which allowed the players to take a 10-minute break after the third set -while officials called a halt to junior matches on the outside courts for more than two hours.
“I’m so happy to reach another semi-finals in my favourite tournament,” del Potro said in his on-court interview.
“That’s very special to me. Beating John in these kind of matches is like an epic, an epic match.
“We both were tired in the end, we both fought until the end and I think I survived with my serve.
“That was the only difference I think.”
The pair loaded up and traded service and baseline bombs, the American laying down 26 aces and del Potro 14.
Break chances were few and far between with Isner unable to convert any of his three while del Potro had 11 opportunities and cashed in on three, including one to close out the match.
It was enough to see 2009 champion Del Potro through to the last four in New York for a third time, and second in succession.
He will face top seed Rafael Nadal or Austrian ninth seed Dominic Thiem.
Del Potro could not convert the sole break chance in the opening set with Isner making the most of a mini-break in the tiebreaker.
With Isner showing signs of early distress, del Potro pounced to secure the only break of the second set at 3-1 and that was enough to level the contest.
With neither man able to break the third set went to a tiebreaker which del Potro won to seize the momentum.
The heat break did little to re-energise Isner as del Potro broke at the first opportunity on the way to a 3-0 lead.
Isner was trying to become the first American man to reach the US Open semis since Andy Roddick in 2006.
