Andy Murray spells out where his level is after losing to Frances Tiafoe in Winston-Salem

Andy Murray was left frustrated by some key moments against Frances Tiafoe.

The Briton came close to wrapping up the first set in the 10th game but failed to convert three break points.

A solitary break in the tie-break was enough for the American to take the first set.

Murray, world number 114, lost two straight service games as Tiafoe opened up a 5-1 lead in the second set, but he broke straight back to reduce the deficit.

Tiafoe served out for the match to reach the last 16.

"The positive thing is that I moved well and served well but my level is up and down with no real consistency,” Murray said.

“There are moments in matches where I play well and then I make mistakes or miss returns. I wish I wasn't doing that.

“It's frustrating because if wasn't moving great and not feeling good physically then I would be a bit easier on myself. But when I'm winning a low percentage of second-serve points, that's got nothing to do with the physical side of things.”

“My level is around 50 or 60 in the world.”

Murray will now head to New York for the US Open, the final Slam of the year.

A former champion at Flushing Meadows, he is exceptionally unlikely to repeat the heroics of 2012, but will look at least match last year’s feat of reaching the second round, when he defeated Yoshihito Nishioka before losing to Felix Auger-Aliassime.

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