British two-time champion Andy Murray suffered his earliest Wimbledon exit as he lost in four sets against American John Isner in the second round.

Isner, a 2018 quarter-finalist, fired 36 aces on his way to an impressive victory on Centre Court.

He will play 20-year-old Italian 10th seed Jannik Sinner next.

Murray had never before failed to reach the third round at SW19, in 13 previous attempts.

But he was unable to register a break of serve against the unwavering Isner, who executed his trademark big-serving game to perfection to record a memorable win, going out just hours after British teenager Emma Raducanu lost to Caroline Garcia on the same court.

No way through for Murray against Isner

Feeding off an electric atmosphere to stay in the match, Murray punched the cooling air as a looping Isner return dropped wide to conclude the third set - the crowd rising to their feet to offer further encouragement.

But then came the sucker punch. The Briton, ranked 52nd in the world, rescued one break point for deuce but a second chance proved one too many as Isner took a 3-2 lead in the fourth with the light beginning to fade at SW19.

At 4-2, play was paused to allow the roof to be closed and, following the restart, the American delivered on serve to turn around a 0-30 deficit and move one game from victory.

He was forced to serve out the contest and duly obliged - a love hold sealing a fitting end to an efficient display against the home favourite.

Murray, whose Wimbledon preparations were disrupted by an abdominal injury, had come back to win his opening match against Australian James Duckworth on Monday in four sets.

A fightback was once again required against an opponent he had beaten in all eight previous meetings, however Isner proved an insurmountable obstacle in their first contest on grass.

It was the American 2018 semi-finalist who landed the first blow, drawing a couple of errors from the Scot as he broke to 15.

A superb backhand winner was celebrated by the captivated crowd and helped Murray reach the first of two break point opportunities in the following game, but a series of blistering serves ensured Isner escaped unharmed.

Three comfortable holds of serve, two without conceding a point, enabled the world number 24 to secure the first set relatively untroubled.

In a tight second set, Murray took a moment to compose himself, head in hands, after missing a backhand down the line that would have given him a break point when leading 4-3.

But with neither player faltering on serve, it fell to a tie-break to determine the extent of Murray's task. If he was to continue at SW19, he would have to come back from two sets down for the 11th time in his career.

Twice forced to serve to stay in the tournament when trailing 5-4 and 6-5, Murray called upon his vast experience to twice hold serve to love and reach another tie-break.

And while that one went his way, it was ultimately not to be for Murray and his faithful support as his 14th Wimbledon challenge met a premature end.