Jonny Brownlee was leading the final race in Cozumel, Mexico, at the World Triathlon Series when he began staggering with less than half a mile left on Sept. 18 (video below).
One of the BBC Sport announcers exclaimed: "He's losing his sense of direction, this is worrying. Oh goodness me. This is a horrible sight."
Around that time, Alistair Brownlee came around the corner with Henri Schoeman of South Africa in what was assumed to be a race for second place.
As Jonny staggered off to the side to a water station, Alistair put his brother's arm over his shoulder to help him, while Schoeman pulled ahead.
"Dramatic scenes in Cozumel as the Olympic champion carries his younger brother towards the podium," the announcer added.
"I cannot believe what we are seeing here," a second announcer said. "Is this allowed? Is he allowed to help his brother? Is that part of the rules, I'm not too sure. We've never seen anything like this before."
Schoeman ended up winning the race, and when the British brothers got to the finish line, Alistair gave Jonny a push across for second place, notes The New York Times.
After collapsing, Jonny was quickly rushed to a local hospital with a case of severe dehydration.
Someone did file a protest against the brothers, but the ITU Competition Jury ruled the finish to be legal based on Appendix K, Rule 7, that says athletes can get help from another athlete, race official or technical official.
Mario Mola of Spain was the victor of the overall series title, even though he finished fifth in the race.
Alistair told the International Triathlon Union (ITU) website:
I have been in that position before, when it happened to me in London a few years ago, I remember being in second place and then coming around and someone telling me I was in tenth. I couldn’t remember all of those people passing me.
So I swore that, literally if it happened to anyone I would help them across the line. It is an awful position to be in, if he clunks out 1k from the finish line there is no medical support, it is a dangerous position to be in. Obviously the World Series is a big race, but I just had to do what was right in that situation.