Britain's Andy Murray won the Cincinnati Open Sunday when his opponent in the final, Serbia's world number one Novak Djokovic, retired injured.
Murray was already in control and leading 6-4 3-0 when Djokovic, who had received treatment to his right shoulder at the end of the first set, called it quits, raising doubts over his fitness ahead of the U.S. Open.
It was just the second defeat this year for the in-form Djokovic, whose victories this season included the Australian Open and Wimbledon championships, but could not have come at a worse time with the last grand slam of 2011 due to start in New York on August 29.
Djokovic, chasing an unprecedented sixth Masters Series title this season, had struggled from the outset with Murray breaking his first service game.
The Serb showed some discomfort with his shoulder but was still able to break back to 3-3 and bring the crowd to life, in anticipation of a real contest.
But Murray, looking confident and efficient, broke again straight away, finishing off a magnificent rally with a superb cross-court forehand winner.
Murray served out the set and Djokovic called for a medical time-out during the interval, receiving an extensive massage to his right shoulder and upper-arm.
He returned to the court but was in clear discomfort and after dropping his first two service games to trail 3-0, he conceded defeat and came to the net to shake hands with Murray.
It was the world number four's second title in Cincinnati after he also beat Djokovic in the 2008 final and his seventh overall Masters crown and a major boost to his preparations for Flushing Meadows.