Andy Murray
Murray to face John Isner in quarter-finals. Getty

Andy Murray came from a set behind to defeat Gilles Simon at the Vienna Open and keep himself firmly in the race for the No 1 world ranking spot currently held by Novak Djokovic.

Murray, 29, sealed his place in the quarter-finals of the competition after he bounced back after a difficult start to beat Simon 4-6 6-2 6-2. He will take on American John Isner in the last eight.

Thursday's victory was Murray's 12th in a row having already won tournaments at the China Open and Shanghai Masters in October. If he can maintain that winning form in Austria, he can replace Djokovic at the summit of men's tennis next week at the Paris Masters.

Should Murray win in the French capital next week, the Serbian will have to reach at least the semi-finals to cling onto his top spot.

It could have all been very different however after Murray endured a stuttering start against Simon, falling a set behind before breaking early in the second to get back on track. He then fended off six break points from his French opponent to level the contest, winning the last four games in a row.

After a brief delay where Simon received treatment on a severely blistered foot, Murray eased to victory in the third. Murray will meet Isner on Friday for a place in Saturday's semi-finals.