World number one Novak Djokovic has been knocked out of the Madrid Open when he lost 7-6 6-7 6-3 to unseeded Bulgarian Grigor Dimitrov after suffering an ankle strain in the second round.

Djokovic, who had a bye in the opening round, was already a break down to the promising 21-year-old in the second set when he twisted the same ankle he damaged playing for Serbia in the Davis Cup last month.

After a lengthy medical timeout on Tuesday, he managed to break back and saved a match point on the way to taking the tiebreak 10-8 to force a deciding set.

However, the Serb immediately lost his serve for the third time and Dimitrov battled through cramp to secure another break in the ninth game and seal by far the biggest win of his career and end Djokovic's bid for a fourth title of 2013.

Source: Agencies