If Andy Murray wanted an early test of his battling qualities after six weeks out, he got it last night, being made to battle far harder than expected before clinching his place in the quarter-finals of the Valencia Open.

The No 1 seed, still feeling his way back to top form in his first tournament since his recovery from an injury to his left wrist, withstood the challenge from an inspired Leonardo Mayer, a little-known Argentinian ranked No 64 in the world, before moving through to the last eight with a 6-4, 3-6, 6-3 victory.

Murray enjoys few things better than a scrap and the world No 4 certainly found himself in one as Mayer, whose only real claim to fame is that he was born on the same day as Murray, played an attacking, flowing brand of tennis that suggests he is destined for much better things. Far from being overawed, the Argentinian crushed Murray in the second set and pushed him hard in the third before finally succumbing.

Murray will play Albert Montañés, the Spaniard, today for a place in the semi-finals, but for a while last night it looked as if he would have a few extra days off before his next tournament, the BNP Paribas Masters, which begins on Monday. Mayer played aggressively and took away the net from Murray at every opportunity. In the end, it took some typically robust play from the Scot to stop him from snatching a surprise win.

“Obviously I’m disappointed every time I lose, but [this week] it wouldn’t have been the be-all and end-all,” Murray said. “I wanted to try and play matches before Paris just to see where I was at. If I’d lost after 2½ hours, I would have been disappointed because it’s quite a long time. But it turned out to be, in the eyes of Alex [Corretja, part of his coaching team] and in my eyes, the perfect match to get myself back in shape.”

Murray broke Mayer in the seventh game on the way to winning the first set. Unusually cold conditions — the doors to the arena were left open — affected Murray, though, and as his concentration wavered, Mayer stormed 5-0 ahead in the second and held on to level. Mayer stayed with Murray at the start of the deciding set, but the Scot achieved the break in the sixth game and came from 30-0 down when serving for the match to complete a hard-fought win.