World number one Andy Murray overcame a sluggish start to earn a battling 7-5 7-5 victory over Gilles Muller on his return to competitive action at the Monte-Carlo Masters.

A three-time semi-finalist in Monaco, Murray made his first clay-court outing of the season on Wednesday, having recovered from the elbow problem that forced him to miss the Miami Open and Great Britain's Davis Cup defeat to France.

It was certainly not plain sailing for the reigning Wimbledon champion, but he was nevertheless able to maintain his 100 per cent record in matches against Muller and book a third-round tie against 15th seed Albert Ramos-Vinolas.

Although he played a charity match against Roger Federer last week, Murray had limited time serving at full pace in the build-up to his return and certainly looked rusty as he was broken at the start of the match, throwing in three double faults.

Break points were saved in each of the next two games, but Muller appeared confident and in control, varying his play to good effect as he closed in on sealing the first set.

However, after spurning two set points on the Murray serve at 5-3, the Luxembourger was broken to love in what felt like a key shift in momentum.

Murray duly held to move ahead for the first time and another break gave the Briton the set, a furious Muller smashing his racquet in frustration after a loose volley sealed his fate.

There were further concerns for Murray at the start of the second set as he again gave up his serve and was forced to save two further break points, one with the aid of a lucky bounce off the net cord, after immediately getting back on level terms.

Muller continued to stick with his illustrious opponent and showed impressive resolve to hold for 5-5 after two wonderful lobs had got Murray to 0-30.

A stunning cross-court backhand winner earned Murray a match point in Muller's next service game, though, and it was converted at the first attempt as the world number 28 slapped a forehand wide.