Andy Murray was tired but happy after coming through a gruelling three-set showdown with Cameron Norrie to book his place in the quarter-finals at the China Open.

The 32-year-old claimed his first back-to-back Tour singles wins since undergoing hip surgery in January with a 7-6(6), 6-7(4), 6-1 victory over his fellow Briton in Beijing to make the last eight for the first time in 12 months.

However, he had to dig deep to do so, battling through fatigue in the second set before surging across the finishing line to set up a showdown with either top seed Dominic Thiem or Chinese wild card Zhang Zhizhen on Friday.

There were flashes of the touch and plenty of the grit which took the former world number one to the pinnacle of the game in a contest which lasted two hours and 52 minutes.

Murray told www.atptour.com: "I'm tired – I just had a sleep before coming. I'm really tired.

"That's the first time I've had to do that since I came back. It's something that I need to kind of get used to again, especially playing at this level and that intensity.

"It was a good step for me. It's great that I won the match. Whether I'd won or lost it, I was able to come out the following day and be competitive and play some good tennis.

"But obviously I'm happy I've got the day off tomorrow to recover."

Murray said: "The good thing about tennis is that you can change strategy and tactics.

"If you watched the end of the second set, pretty much the whole of the third set, I tried to keep the points short. I started coming to the net a lot more. My feeling was that the average rally length went down by quite a few shots.

"In the third set, I didn't really feel like out of breath after any of the rallies, whereas in the middle of the second set, I felt like there were three or four games where we were playing a lot of long points, but he was also dictating the rallies."