Having claimed bronze in London nine years ago and silver in Rio behind his brother Alistair, Brownlee finished fifth in the individual race on Monday but he played a key role in Britain’s third triathlon medal of the week.
After an excellent first leg from Jess Learmonth, Brownlee broke away from his rivals, and individual silver medallists Georgia Taylor-Brown and Alex Yee maintained the advantage to claim Britain’s seventh gold of the Games.
“The Olympics, I’ve completed it,” said an excited Brownlee to the BBC immediately afterwards.
Having been in the shadow of his brother for his entire career, Brownlee now finally has his gold – the third for the Yorkshire siblings in a remarkable family haul.
The 31-year-old said: “It’s about time. I keep on trying to get gold medals, Alistair’s won two so far, and to go home with one and get towards matching him is super special.
“And it’s also the first ever (Olympic) mixed team relay in triathlon so we’ve made history in that. I feel like I’ve been a part of a lot of history in my career and that’s just another one. It’s capped off my Olympic career amazingly.”
Alistair was watching from the sidelines having seen his qualification hopes ended by an ankle injury, and was delighted for his brother.
“I know for a long time that he’s wanted, gold,” said the 33-year-old. “And he never wanted to touch my medals. He thought it was bad luck. It’s awesome for him and I’m really happy.”
Brownlee plans to leave Olympic distance behind and move onto longer events but his performance here might just give him second thoughts.
An excellent opening leg from Learmonth ensured Britain were part of a lead group including the United States, Holland and Germany, and Brownlee then produced the fastest leg of the day to give Britain a nine-second advantage.
Taylor-Brown extended that to 22 seconds, putting her fellow individual silver medallist Yee in an extremely strong position heading into the final leg of a 300 metres swim, 6.8 kilometres bike and 2km run.
But hunting down the 23-year-old was French double world champion Vincent Luis, who produced a scintillating swim and caught Yee going into the second lap of the bike.
Yee managed to catch his wheel, though, and another impeccable transition saw him surge on to the run in first place.
He never looked like being caught, opening up an 11-second lead on the first lap as Luis’ efforts caught up with him and American Morgan Pearson moved into silver.
Yee was able to run alone down the finishing straight before celebrating with his jubilant team-mates, and Brownlee said: “It’s super special. The way we all raced today was amazing.
“Jess set us up perfectly, we didn’t make any mistakes, we did everything as well as we could and Alex finished it off. To finally get a gold medal, I’m quite emotional.”