Andy Murray was filmed berating his support staff with an expletive midway through the Wimbledon men's final after his coach Ivan Lendl apparently went for a toilet break during a nail-biting tie-break.
The world No 2 was caught on the BBC's live broadcast shouting "b***s***" and gesticulating wildly after going two sets ahead and inching towards his second All England Club crown.
Murray, 29, is believed to have spotted his tempestuous coach Lendl, 56, getting up and leaving after the player had won a crucial point.
Footage of Murray's furious response was caught on the live afternoon broadcast as a record 18 million were estimated to be tuning in for the encounter against Canadian Milos Raonic, 25, the sixth seed.
The flare up took place as the Duke and Duchess of Cambridge looked on from the royal box, joined by Prime Minister David Cameron, Scotland's First Minister Nicola Sturgeon and Hollywood stars Benedict Cumberbatch and Bradley Cooper. Viewer totals were predicted to be both Wimbledon's biggest-ever and Britain's biggest TV audience for two years.
A peak audience of 17.29 million watched Murray's 2013 Wimbledon final win. Wimbledon's all-time record stands at 17.3 million for 1980's Bjorn Borg v John McEnroe final.
Full-scale "Murraymania" had gripped the All England Club earlier as fans queued in drizzly rain from the early hours in the hope of securing tickets.
Murray had warned earlier his Canadian opponent he would be "ruthless" in his quest for a third Grand Slam. But commentating on the BBC, former semi-finalist Tim Henman said Murray had come into the tournament with a quiet confidence.
Henman sent Murray a good luck text before the tournament and received a reply which said, "I have got a good feeling about this one", with a little "fist bump" emoji.