Serb And Volley: Djokovic Ends Millman's Dream US Open

John Millman's giant-killing run has come to an end.

Australia's new tennis golden boy has been knocked out of the US Open in straight sets, losing 6-3, 6-4, 6-4 to Novak Djokovic.

It was a nervy start for Millman, who was making his Grand Slam quarter-finals debut. The Australian was broken on his first serve and couldn't find a break to get him back into the first set. Both players made a large amount of unforced errors, particularly on the backhand.

Millman's first service game of the second set seemed to tell the same story as the first, but the Aussie saved three break points.

Image: Getty

But as has been the story of the tournament, the heat played havoc on the players, both dripping with sweat. Djokovic in particular looked to be fading as the temperature took its toll.

Tied at two-all in the second, Millman stopped the game to have an outfit change, apologising to his opponent for the interruption.

Image: ESPN/ US Open

Djokovic was more than happy to oblige, telling Millman: "I could use the break", before kicking back and waiting for his opponent to return from the changing rooms.

But the relaxation ended there, with the Serb erupting at his box. Minutes later an energy drink and unlabelled pills made their way into Djokovic's hands.

The extended break and supplements worked in favour of Djokovic, breaking the Aussie at 5-4 to take to out the second set.

It took Djokovic just three games in the third set to break Millman, after the Australia double-faulted to give him the chance.

Millman fought back and brought the set back to being on serve, but the Serbian was too strong and broke back to take it to 5-4.

With three match points is his pocket, nothing was getting in the way of Djokovic, who finished off the match with a backhand volley to advance to his 11th straight semi-final, against Kei Nishikori.