Novak Djokvic took on Gael Monfils in the first men's semi-final of the U.S. open with the Serb looking to successfully defend his title at Flushing Meadows. His opponent had lost all 12 previous encounters between the pair and in the sweltering New York temperatures, the Frenchman would find it difficult to avoid a 13th.

The world number 1 takes the first set 6-3 and continues that form in to the second.  Here at set point his French opponent shows some fantastic athleticism before being is undone by this forehand winner which sees Djokvic take the set 6-3. Monfils would appear to be limping at the end but is able to continue.

The 30-year-old shows signs of a comeback in the third. With Djokovic serving he again shows off some impressive stamina and jumps high in the air to land this volley on his way to taking the set 6-3.

But Djokovic soon re-asserts himself in the contest and comes back strong in the final set. At match point Monfils looks to be tiring when his serve is fired back at him as the 12 time grand slam winner wraps up the match 6-3, 6-2, 3-6, 6-2, to stay on course for a second U.S. open title.

In the other semi-final Kel Nishikori is taking on third seeded Stan Warrinka.

And its the Japanese who has the better of the opening stages. The 26-year-old is able to break his opponents serve with this volley on his way to taking the first set 6-4.

The Swiss, who defeated Andy Murray in the last 8, levels the match up with a 7-5 win in the second and he then takes the third 6-4 when Nishikori fires the ball beyond the baseline.

The humidity of the big apple eventually takes its toll on Nishikori and with Wawrinka at match point in the 4th he fires his return into the net which seals a 4-6, 7-5, 6-4, 6-2 win for his opposite number and a show down with Djokovic in Sunday's final.