Jonny, 26, third in London four years ago, went one better this time to take silver after being outkicked by his 28-year-old brother in the heat of the concluding 10km run. Henri Schoeman took the bronze, the first medal for South Africa in the sport since it was introduced in 2000.
The brothers delivered a textbook performance after coming out of the 1.5km sea swim off Copacabana beach and controlling the 40km bike leg. They then surged clear on the 10km run, defying the heat, to claim first and second place.
Alistair admitted he had pushed himself to the limits in the pursuit of victory. “Every day has been so hard. I have woken up in pain every day,” said the champion, who underwent extensive ankle surgery last year.
“We wanted to get gold and silver four years ago, but this time we pulled it off. When Jonny crossed the line, I said to him, ‘We’ve done it’. To see your little brother come over the line 10 seconds after you is phenomenal. It’s so satisfying.”
On his rivalry with Jonny, he said: “We get asked this a lot and we’ve never had a great answer to it. It’s been going on since we were three years old. Competing at football, table tennis, running round the garden – it’s something we’ve always done. But getting gold and silver has come from working together. If I’m having a bad session, he pushes me and the same the other way round.”
Looking back on the race itself, he said: “We knew the first two laps on the bike would be crucial. The last few weeks we have been training to commit and boy, we did. When we got to the halfway mark I knew we were going to get two medals and then it was just a run for it.
“I was pretty confident we would get first and second but I didn’t know which way round it would be. I just had the edge on Jonny but he has killed me in training every day. We have been pushing each other to the max. I wasn’t sure I would win. I knew had to go through hell and I did.”
Slovakian Richard Varga, as expected, led the field out of the 1.5km sea swim but the Brownlee brothers were right behind him. South African Richard Murray and Spain’s Mario Mola, expected to be among the main challengers, were almost a minute back, with their chances already virtually over.
The Brownlees took the initiative in the lead pack of 10 bikes, driving hard up the first steep hill on the first lap of eight, and never looked back. By the halfway mark on the bike, the chase group were 73 seconds adrift and out of contention. Despite baking heat, the Brownlees continued to drive up the two climbs from the front of the group. The lead group stayed together into the second transition but within the first few metres of the run the Brownlees and France’s Vincent Luis forged clear. After the first of four laps, however, the two Britons had pulled away and it was going to be yet another head-to-head family duel.
The brothers worked hard to cope with the effects of the heat having both suffered in previous races, but by the 5km halfway mark they had forged 13 seconds clear of Schoeman. They then ran shoulder to shoulder before Alistair stamped his authority on the race by driving clear on the third lap.
Runner-up Jonny said: “I’m used to getting beaten by Alistair but I‘ve gone better than last time in London when I got the bronze. I’ve actually been training a bit better than him and if it had come down to a sprint, I could have won. Maybe in four years, he’ll be older, slower and greyer.”