Younger brother Jonny was leading the race in Mexico and on the verge of capturing the series title when he started to stagger along the road as exhaustion hit him at the end of the hot course.
Fortunately Olympic champion Alistair came along to help him across the line in second place like a fucking legend, after South African Henri Schoeman had overtaken them to take the win. Unfortunately it wasn't enough for Jonny as Spain's Maria Mola finished in fifth to take the title.
However, the race will be remembered for the scene at the finish line with Alistair almost dropping Jonny ahead of him.
Olympic silver medalist Jonny was taken to the hospital after collapsing over the finish line but did tweet a picture from his hospital bed on a drip to prove he was okay.
Following the race, Alistair said he would have helped any athlete over the line after a similar thing had happened to him earlier in his career. What a hero.Not how I wanted to end the season, but gave it everything. Thanks @AliBrownleetri, your loyalty is incredible pic.twitter.com/6uG4QiIgfS— Jonathan Brownlee (@jonny_brownlee) September 19, 2016
He also took the piss a bit out of his brother, because that's what you do, and said he could have run a better race. He joked: "I wish the flippin' idiot had paced it right and crossed the finish line first. He could have jogged that last two kilometres and won the race."
The Spanish Triathlon Federation lodged an appeal against Jonny's second place but the ITU dismissed it out of hand because 'athletes can receive help from another athlete'.
The British brothers won gold and silver at the Olympics last month following gold and bronze medals four years earlier in London.