Andy Murray moved into the last eight of the Valencia Open after surviving a tougher than expected workout against world number 64 Leonardo Mayer in Spain.

The top-seeded Scot produced an inconsistent performance in his second match since a six-week injury lay-off, but came good in the decider to win an entertaining tussle 6-4 3-6 6-3.

Murray struggled to get into his rhythm from the start, while Mayer served confidently until the ninth game - which the Scot seized on his first break-point chance, before serving out to take the set.

The second set proved a disaster for Murray, who let his concentration suffer and found himself 4-0 down against an opponent clearly gaining in confidence with each game.

After going a further game behind, Murray staged a mini revival - winning three games on the trot to at least give the set a semblance of respectability, before Mayer served out at the second attempt to draw level.

The decider was a cagey affair. But Murray struck in the sixth game, pressuring the Argentinian's serve and converting his second break-point when a sharp return induced a long forehand response.

Mayer was still far from finished, a super cross-court forehand taking him to 0-30 when Murray served for the match, and nervelessly rescuing the first two match-points against him.

But the Scot held firm, forcing a forehand error from Mayer to set up his third opportunity - which he finally took with an ace, marking his moment of triumph with a roar of relief.

Murray will know he needs to improve for his last-eight clash with Spaniard Albert Montanes - who was given a valuable day's rest when his opponent, eighth seed David Ferrer, withdrew with an ankle injury.