It started with a slip, and ended in yet more swimming glory.
As she cradled her first Olympic medal at her debut Games, Dawson could not quite explain what had gone wrong at the start of a race Britain were favourites to win after qualifying fastest from the heats.
“I couldn’t quite feel my hands,” she said. “Somehow I slipped going in. I wasn’t quite sure what I did, when I did it. I think I managed to keep calm and after that it was about focusing to try and get the best performance I could out of myself by the end of it.”
She did just that, recovering to swim an excellent leg before Peaty and Guy - already gold medalists at these Games - reeled in the leaders and handed over to Hopkin, under the added pressure of replacing Freya Anderson for this final, to swim them home on the freestyle.
Mixed relays have been criticised in some sports, most notably in athletics, where the sight of men towering over their female competitors as they charge past hardly does wonders for the image of women’s sport, lending itself to casual criticism from those unwilling to take a holistic view.
Last night’s first 4x400m heat on the track brought a case in point, as Nigeria’s Patience Ikon George, the only female runner on the anchor leg, went from first to last over the course of the final lap. The fault in her country’s exit was, of course, as much to do with her male team-mates failing to establish a sufficient lead, but it not stop the detractors gleefully sharing clips on social media.
At the Tokyo Aquatics Centre, however, it was a superb spectacle. With the intrigue of different strokes added to a mixed order, there was never any pretence that male and female swimmers are supposed to be directly comparable on their respective legs. The result was a glorious, chaotic stream of staggers that both unwound and became more muddled as the race wore on, regardless of the gender of the people in the pool. Only once the final wall was touched were you truly sure where anyone stood.
US star Caeleb Dressel, the individual 100m freestyle champion, was asked what it was like racing against women on the last leg. His response? “Well, I didn’t catch any of them, did I?”
Hopkin was one of those the American tried and failed to reel in. “It’s pretty cool to say I’ve beaten Caeleb Dressel!” she said. “But I didn’t look at where he was; I think that would have taken my focus away from what I was doing. It’s pretty cool to be in the same race as him.”
Peaty, meanwhile, was asked whether he felt any sympathy for America’s Lydia Jacoby, the individual 100m breaststroke champion but also a 17-year-old girl, as he steamed past. He did, he admitted, but only due to a wardrobe malfunction, not because of her sex.
“My only bit of remorse, and I felt bad for her, was when I saw her goggles come off,” he said. “That is hard to take as a junior. She will learn from that and that is what sport’s about.”
Being behind is not a position the 26-year-old has found himself in too often over the past five years, and diving into the pool at the end of Dawson’s backstroke leg, he admitted he had to keep a lid on things.
“The strategy is not about getting me pumped up. It’s about getting me pumped down,” he explained. “That might sound silly but if I see somebody ahead of me I just want to go, I just see red mist and it’s ‘I’ve got to get you!’
“So, really it was about the first 50m, control. Control. Control. Then as soon as you come off that wall, everything. All the emotion. Everything.”
Another reason for the failure of mixed relays in some other sports is their status as a consolation prize, an afterthought to individual events and a benefit race for whoever has the greatest strength in depth - usually the Americans.
That was never the case here: Dressel was swimming his third event of the morning session and before her closing leg, Australia’s Emma McKeon had leapt into the diving pool to keep warm after breaking the Olympic record in her 50m freestyle heat literally five minutes earlier.
For Britain, Guy had made the ultimate sacrifice, pulling out of the individual 100m butterfly earlier in the day to focus completely on the relay. His performance suggested he would have been in contention for a medal.
“It was a hard call to make,” he said, having already tasted relay glory with the men’s 4x200m freestyle team earlier this week. “I had a chat with my coach and he said ‘listen, you could do something really important and cool here’. He asked ‘Can you do your best time after swimming the 100m butterfly? That’s the risk you’re taking’.
“I’ve got two Olympic golds and nobody can take those things away from you.”
Britain now have four and, who knows, by this time tomorrow, perhaps an unprecedented fifth. They are the world champions on the male-only equivalent of this race and their tussle to with the Americans should prove a suitably thrilling climax to what has been a phenomenal meet.
Whatever happens there, history has already been made.