Novak Djokovic survives heat to reach US Open final

The world number one was belatedly pushed by the unpredictable Frenchman, but he dealt with the extreme humidity better to win a crazy encounter 6-3 6-2 3-6 6-2.

Djokovic was treated for various shoulder complaints as temperatures hit 33°C, while Monfils was often found keeled over – head propped on racquet handle – desperately willing air into his lungs.

The 29-year-old will go for a third US Open title against Stan Wawrinka, a four-set victor of Kei Nishikori, in Sunday’s final.

The pre-match analysis focused on Djokovic’s troublesome left wrist, with the Serb reaching the last four unscathed after a second-round walkover and two further mid-match retirements.

However, it was a flickering screen in Arthur Ashe that caused him the most grief early on as he almost surrendered a 5-0 lead in the opening set.

He crept over the line, with Monfils blowing two break points to bring it back on serve, before easing through the second set.

An early break in the third and the contest appeared to be over, but Monfils suddenly mounted resistance – geeing up the crowd with bursts of trademark athleticism as he reeled off five straight games to flip the set on its head.

This newly-discovered enthusiasm came at a price, though, with Monfils pleading for air after every multi-shot exchange.

He still took the set, and broke back in the fourth, but ultimately the conditions took their toll as Djokovic outlasted him to reach a seventh final at Flushing Meadows.