SPORT: DJOKOVIC KNOCKS MURRAY OUT OF US OPEN
Andy Murray is out of the US Open after a brutal quarter-final against Novak Djokovic.
The world number one took the game three sets to one.
Murray looked to be struggling with a back injury for the final set.
Djokovic will now play Kei Nishikori in the semi-finals.
Serena Williams booked her place in the last four with a straight sets win against Flavia Pennetta.