The 28-year-old from Leeds dominated the race in Hyde Park four years ago to fully justify his tag as favourite and goes into today’s Rio 2016 showdown once again as the man to beat.
Not that the intervening four years have been smooth at all. Brownlee has won plenty of races but also struggled with injury.
Last August he took the decision to undergo ankle surgery in a bid to cure the problem once and for all and the gamble appears to have paid off.
Despite not being confident about his form, he streaked away from the field to win the inaugural World Triathlon Series race in his home city of Leeds in June.
It was his first major victory for a year and he followed it up with another excellent performance to win in Stockholm three weeks later.
The worrying news for his rivals is that Brownlee feels he has stepped up the pace significantly during a four-week altitude training camp in St Moritz and then at the team’s holding camp in Brazil.
He said: “I think I’ve trained as hard as I can. We’ve done some really, really good sessions.
“I felt good after coming down from altitude. I couldn’t be happier with my form at the moment. Now it’s just putting the finishing touches to it and making sure I can be in the best shape possible.
“Leeds was amazing and Stockholm went really, really well, and I’ve come a long, long way since then.
“I feel like I’m in my best shape since London.
“It’s given me a lot of confidence after an up and down last few years. I’m in the best possible position. I’ve just got to go out there and do the best I can.”
Only two men – Simon Whitfield of Canada and New Zealand’s Bevan Docherty – have won multiple medals since triathlon was introduced to the Olympic programme in 2000.
There is undoubtedly pressure on Brownlee – not least from his younger brother and biggest rival Jonny – but he should not have any problem putting it to one side.
“Nothing can compare to the expectation before a home Olympics,” he said. “This feels more relaxed.”
Straight after the men’s triathlon, Leeds boxer Nicola Adams fights for her place in a second successive Olympic women’s flyweight final.
The history-maker from London – who is already guaranteed a bronze – faces Ren Cancan of China, the opponent she defeated in the Olympic final four years ago.