Californian Jack Kuenzle has set a new Bob Graham Round speed record, knocking almost half an hour off Kilian Jornet's time.
The former US Navy Seal completed the 66-mile loop, which takes in 42 fells and 27,000 feet of elevation gain, in just 12:23:48.
Catalan running legend Jornet previously held the speed record at 12 hours 52 minutes, which he ran in 2018.
Running the entire Lake District route shirtless, Kuenzle finished at 6.30pm on Friday 2 September.
The challenge was established by Bob Graham in 1932, when he ran it in under 24 hours. It is a rugged, technical route with steep scrambles and boggy tracks which include Scafell Pike, the tallest mountain in England.
But it was no match for running coach Kuenzle, who focuses on setting speed records across the world.
In April he summited and descended Mount Hood in Oregon, scaling 5,254 feet of elevation gain, in the record breaking time of 1:31:31.
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