Roger Federer was stunned by Juan Martin del Potro in four sets in the US Open quarter finals, ending hopes of a blockbuster semi final with Rafael Nadal.
Federer often looked nervous and frustrated in the near three hour contest, and Del Potro pounced on his uncertainty to claim a 7-5 3-6 7-6(8) 6-4 victory.
World No.1 Nadal had earlier kept his end of the bargain by sweeping aside 19-year-old Andrey Rublev 6-1 6-2 6-2, but Federer’s surprise defeat means the US Open is incredibly still yet to host a match featuring arguably the two greatest male players of all time.
Del Potro , who also beat Federer in a classic 2009 final at Flushing Meadows to win his only grand slam title, said after the match: “I think I played my best match of the tournament so far.
“In the tiebreak I got a bit lucky, but after that in the fourth set I played even better and in the end I think I deserved to win.”
Federer accepted that he was beaten by the better player on the night, but bemoaned making too many errors at costly moments of the match and hinted that he was still being troubled by a back injury,
He said: “He was better today, he came up with the goods and I helped him a little bit.
“I missed too many balls to keep me ahead in the match, but I knew going into the tournament that I wasn’t in a safe place.”
The opening set was a cagey affair, but a late surge from Del Potro saw him break Federer before serving it out with ease to take the lead.
The Wimbledon and Australian Open champion was starting to get more of a read on the Del Potro serve though, and he got the better of a series of bruising exchanges to break early in the second set.
That break was enough for Federer to level the match at a set apiece, but an untimely double fault gifted the giant Argentine the advantage at the beginning of the third.
Remarkably Del Potro returned the favour when leading the third set 4-2, and it was ultimately decided by a tiebreak.
Federer had four set points, but some bizarre misses that summed up his night somehow saw Del Potro take a tiebreak that was low on quality but high in drama 10-8.
The situation was looking increasingly bleak for Federer, and Olympic silver medalist Del Potro landed a return winner to break serve midway through the fourth set.
Fans in the Arthur Ashe Stadium still harboured hopes of a Swiss comeback, but Federer was out of ideas and Del Potro was able to comfortably close out another famous win in New York.