Andy Murray claimed the biggest win of his comeback and a place in the last 16 of the Western and Southern Open on Monday by taking out self-destructing fifth seed Alexander Zverev 6-3 3-6 7-5.

Murray offered hope he was on the right track after his injury woes with a tidy first-round win over Frances Tiafoe on Saturday but it is Monday's win over the big-hitting German that will provide a huge confidence boost in the run-up to the US Open that starts next week.

Neither player will include the contest in their career highlight reels, particularly a scrappy third set that was riddled with unforced errors and momentum swings.

Murray jumped ahead 4-1 in the third but was left mumbling and scolding himself as Zverev broke the Briton twice on his way to sweeping the next four games and taking a 5-4 lead.

But serving for the match Zverev double-faulted three times to gift Murray a break and extend the match.

Murray then held serve and finished off the crumbling German, with the help of two more double faults, with a final break to register his first win over at top-10 ranked opponent since 2017.

"It was a big one to get through," said Murray. "I'm satisfied to get through it against a top player having not played for such a long time and I get another opportunity to compete again tomorrow.

"This will give me an idea of where my body is at," said Murray, a past winner of the tournament, which is normally held in Cincinnati but was moved this year in order to get players inside a 'bubble' ahead of the US Open.

Next up for Murray is Milos Raonic, who advanced with a 6-3 7-5 victory over Dan Evans.

Novak Djokovic had withdrawn from a doubles match due to a neck issue and showed signs of discomfort in a 7-6(2) 6-4 win over Ricardas Berankis.

"It's getting better ... it's not yet where I'd like it to be but it's heading in the right direction," said Djokovic, who meets Tennys Sandgren next.

Filip Krajinovic stunned second seed Dominic Thiem 6-2 6-1 and next plays Marton Fucsovics, who beat Grigor Dimitrov 7-5 4-6 6-2.