Novak Djokovic of Serbia (Photo: AP)
Murray produced a dazzling first set against the world number one but could not sustain it as Djokovic moved clear at the top of Group A.
Should Jo-Wilfried Tsonga defeat Tomas Berdych in the day's other singles Djokovic would be assured a semi-final berth with one round-robin match to play.
World number three Murray conceded a mere three points on his serve in a dominant first set but Djokovic got a foothold into the match when he broke the Murray serve for the first time in the sixth game of the second.
Djokovic struck first in the deciding set and had two points for a double break of serve, only for Murray to roar back to 4-4. The Scot then undid all his good work to drop his serve at 5-5 and Djokovic sealed victory after two hours 34 minutes.
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