Former world no.1 Andy Murray has taken another big step in his comeback from hip surgery by beating fellow Brit Kyle Edmund 7-6 (4) 1-6 6-4 in the second round of the Citi Open.

The 31-year-old Scot blasted a backhand cross-court return winner on match point to end the two-and-a-half hour contest and dispatch the fourth seed on Wednesday.

Next up for Murray is a third-round battle with Marius Copil on Thursday. Murray won their only previous meeting last year in straight sets.

Murray, who has added the China Open to his schedule in October as he continues his return from hip surgery earlier this year, said his body was being put through the wringer at the hardcourt tournament.

“I feel better than I did during the grasscourt season, which is positive,” said Murray.

“So things are still getting better and I’ve lasted fairly well through two long matches here on a tough surface on the body so hopefully I can keep healing up from the matches and feeling better.”

Elsewhere, top seed Alexander Zverev won 82 per cent of his first serves in his rain-interrupted match that started on Tuesday against Malek Jaziri en route to a 6-2 6-1 win over the Tunisian.

And earlier on Wednesday, Nick Kyrgios withdrew from the tournament with a hip injury, another setback in the Australian’s buildup to the US Open.

The fifth seed made the trip to Washington hoping to be fit, only to pull out of his opening match against compatriot James Duckworth.

The world No.17 is scheduled to play tournaments in Toronto and Cincinnati before the US Open, which begins on August 27.

Jason Kubler was awarded Kyrgios’s spot in the draw but the lucky loser was unable to take advantage, falling 1-6 6-2 7-6 (5) to Duckworth.

Also in the second round, Denis Shapovalov fired his 15th ace on match point to complete a 3-6 6-1 6-4 victory over Russia’s Daniil Medvedev.