British No.1 Kyle Edmund lost his cool in the Florida sun as he was beaten in straight sets by John Isner in their fourth-round match at the Miami Open.

After Isner claimed the opening set on a tie-break, Edmund had recovered to force another in the second.

However, when serving at 3-5 down, there was a shout of "out" from the crowd following a return from the American down the baseline.

The players continued, Edmund having raised his hand to the chair umpire, who then called a halt a couple of shots later.

The Briton was told by Brazilian Carlos Bernardes: "It is the public . . . you cannot stop like this, it is the person from the crowd."

Edmund replied: "I didn't stop", then added: "You have no control . . . they keep shouting at every point . . . unbelievable."

The Herald:

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Edmund was ruled to have lost the point, which left world No.9 Isner 6-3 ahead and serving for the match.

After another heated exchange with the chair from the Briton before play eventually resumed, Isner produced his 17th ace to seal his place in the quarter-finals with a 7-6 (5), 7-6 (3) win in one hour and 43 minutes which keeps him on course for a successful title defence.

There was little sign of the drama to follow as Isner had earlier looked to have taken control of the opening set when a break and then a hold saw him move 5-2 ahead.

However, as the sun on the Stadium Court continued to impact serving, Edmund – who beat Milos Raonic in round three – recovered to break back and level at 5-5 before forcing the tie-break.

The Briton, No.22 in the world, then produced an early mini-break on Isner's serve to move 3-0 and then 4-1 ahead.

Isner, though, responded to level at 5-5 after two mini-breaks with another handing him a set point which the American confidently dispatched on serve.