Get the latest from TODAY
As British triathlete Alistair Brownlee headed down the home stretch of a race in Mexico on Sunday, he had a choice between speeding for the win or slowing down to help his brother, Jonny Brownlee, whose body had locked up and left him staggering toward the finish.
Alistair, 28, didn't hesitate: He put family first and wrapped his arm around younger brother Jonny.
Alistair assisted Jonny to the finish line while South African Henri Schoeman sped by for the win in the final race of the World Triathlon Series in Cozumel.
Alistair even gave Jonny a last nudge to send him across the finish line ahead of him for a second-place finish, before letting him go. Jonny, who collapsed shortly after, was taken to a local hospital for dehydration.
"If it had happened to anyone, I would have helped them across the line," Alistair told The New York Times. "It’s an awful position to be in. If he conked out before the finish there, and there isn’t medical support, it was a dangerous position to be in."
The official rules allow a fellow runner or race official to help a competitor across the finish line once it becomes apparent he or she is not able to continue on their own.
Alistair's nudge to give Jonny second place also allowed Jonny to finish second in the overall standings for the season in the World Triathlon Series, while Alistair finished 10th overall. Jonny later thanked his brother on Twitter, writing "your loyalty is incredible."
The two brothers are not just any triathletes, either. Alistair is the only male Olympian in history to win two gold medals in the triathlon, taking first in London in 2012 and again last month in Rio de Janeiro. Jonny won the silver in Rio behind his brother and took home the bronze in London.
Alistair's act of sportsmanship was reminiscent of a scene at this summer's Olympics in which U.S. runner Abbey D'Agostino collided with New Zealand's Nikki Hamblin in the 5,000-meter race and then helped Hamblin up so they could both finish the race. D'Agostino tore her anterior cruciate ligament (ACL) in the fall, yet made it the final mile as the two runners helped each other before collapsing across the finish line.
"I think we were both speechless at the fact that we were able to share a moment like that,'' D'Agostino told TODAY afterward. "We both realized it was about so much more than our performance that day."
Follow TODAY.com writer Scott Stump on Twitter.