The Russian looked out of sorts early on Centre Court as he lost the first set on a tiebreak to the Frenchman in their first ever Tour-level meeting and had to save a set point to avoid going down 2-0.

However, Medvedev, runner-up at the Australian Open, found a bit more of his usual groove to level the match with a tiebreak before outlasting a strong Muller to clinch the third set and then the match over three-and-a-half hours.

The Russian reached the semi-finals last year at the All England Club but was made to work hard for the win by Muller who kept pace with the Russian despite needing a medical timeout for a left thigh issue before the fourth set.

The Frenchman delighted the crowd with some unconventional shots, including underarm serves and tweeners. However his inexperience on the surface, having won only three matches on grass in his career, showed as Medvedev stepped up his attacks at the net after losing the first set.

The move paid off, though the pair took turns in trading breaks over the second and third sets.

Medvedev, watched on by compatriot and 2004 Wimbledon champion Maria Sharapova in the Royal Box, was not at his clinical best but forced Muller into making crucial errors, such as a failed drop shot that gave the Russian the third set.

The fourth set looked to be heading to a tiebreak before Muller gave up two match points on his own serve. A double fault on the second gave Medvedev the win and passage to the next round.

"When you win, there is the next round to try and do better," the former world number one said on court.

"For some reason it (the grass) feels really slow, I need to get used to it but the more matches I play on it the more chances I have to play better... (I'm) happy to play on Centre Court at Wimbledon but even more happy to win."