American marathon swimmer Sarah Thomas on Tuesday became the first person to swim four times across the English Channel in a row.
Thomas, 37, set off from Dover on Sunday morning and completed the gruelling feat in 54 hours and 13 minutes, according to a swim tracker.
The Channel Swimming & Piloting Federation congratulated Thomas for completing the four-way historic crossing," describing the swimmer as "an absolute legend!"
Lewis Pugh, a British-South African athlete who was the first person to complete a long-distance swim in every ocean in the world as well as the first swim across the North Pole, said Thomas's achievement is "extraordinary, amazing, super-human".
"Just when we think we've reached the limit of human endurance, someone shatters the records," he added.
Thomas started her long-distance swim career at age 25 and did her first Channel crossing in 2012. Five years later she also became the first person to complete a "century" swim of over 160km in neutral water.
But four months later she was diagnosed with an aggressive form of breast cancer. She was given the all-clear in the summer of 2018 and notched up her training again for her next challenge.
Joe Washer and Elaine Kornbau Howley, who are making a crowdfunded documentary on the swimmer, released some footage of Thomas swimming the Channel.
When she finally made it back to British shore early on Tuesday morning, Washer revealed that she celebrated with a bag of M&Ms.
The new record-holder, meanwhile, simply wrote on Facebook: "Whoa. Ouch."