Andy Murray rallies past Mackenzie McDonald in test of hip

"If I only play one or two tournaments and then take a break for a month, it's just hard to get into that routine", Murray said.

"I wasn't dictating numerous points. It was nice to get it".

"I hadn't played in darkness or under the lights in a really long time and I felt my rhythm was off", Murray said.

He told Sky Sports: 'It's obviously not where I would want to be ranking-wise but the good thing is that when you are right at the top of the game it's not easy to move up just one spot.

The tournament will be Murray's third since hip surgery in January and mark his return to the hard courts for the first time since March 2017 at Indian Wells.

"I have to see how the body responds to that, not just the hip".

But a single break of serve in the sixth game of the second set was all it took for Harrison to pull level.

He added: 'It wasn't so much thinking about hanging the rackets up, I've always planned and wanted to come back.

Playing in just his third tournament in almost a year, the former world No. 1 is trying to raise his ranking back up from its current standing of No. 832.

Murray - whose opening-round clash did not get underway until 10pm local time as rain wreaked havoc in DC - will face countryman Edmund again.

He later overcame Stan Wawrinka at Eastbourne, only to lose in straight sets to Edmund two days later and then withdraw from Wimbledon.

Murray also spoke on working for BBC as a commentator during Wimbledon, and in particular for the quarter-finals match between Juan Martin del Potro and Rafael Nadal: 'It was fun to do it and it was the first time in a long time that I've watched a match as a spectator.

Elsewhere American Tim Smyczek won his rain-interrupted match against Lithuanian Ricardas Berankis 7-6 (4) 6-2 and will next face Mischa Zverev, who defeated Smyczek in three sets at the Atlanta Open last week.

American Noah Rubin's powerful serving overwhelmed Russian Mikhail Youzhny.

Murray earned five match points but he was unable to put away McDonald, who used his second break point to stay alive on centre court.

Murray has been warming up for his return in the company of former England football captain Rooney, who joined him on court for a lighthearted session.

  • Stacy Allen