Out of a cluttered front bunch as the triathletes wheeled their way up The Headrow in Leeds, two figures decked in black could be seen leaving the rest trailing in their wake.
Alistair and Jonny Brownlee were at the head of the race, talking tactics, cajoling rivals, and all was as it should be in the world.
They each even took turns to launch attacks, Jonny first before he was sucked back into the chase group, and then Alistair, taking Irish rider Russell White with him as they swung through Millennium Square and built an advantage of nine seconds.
Such a sight has become a familiar one in triathlons across the world over the last decade, but what happened next surprised him, his brother and the watching public.
It even left the two-time Olympic champion questioning his future in a sport he has dominated for the best part of a decade.
“We’ll sleep on it. I’ve got to decide over the next few days,” said the 31-year-old after one of his most sobering days as a triathlete.
That burst off the front proved a momentary nod to days gone by as the man who has won everything his sport has to offer – including this race twice – soon found himself off the pace in the 1okm run, which traditionally has been his strength.
Alistair would eventually finish 44th, nine places behind younger brother Jonny who has questions of his own to answer, and a long way short of Australia’s Jacob Birtwhistle, who became the fourth different winner of the four World Series races to have been run this year.
American Matt McElroy beat Javier Gomez in a sprint for second, the Spaniard striking a blow for the old guard despite the travails of the Brownlee brothers, the men he has traded victories with down the years.
“It was terrible,” said Alistair, who denied that he had any ailments despite grabbing his lower back when running through transition. “I just had a really bad day. I don’t know what was wrong with me. When you’re having a bad race everything starts to feel like s**t.
“I’ve been focused on this race for a few months now and the last couple of short-distance races I’ve done have gone really well.
“I was trying to push it but I just didn’t have it.
“It was quite a tough race, but the run was pretty slow. They were just obviously going faster than me.”
So if he stays in triathlon does he believe he can still get back to the top?
“I think so,” he said, hopefully. “I wanted to show myself that I could do it [yesterday].”
While Alistair headed off to contemplate what is next, Jonny was left wondering what he has to do to get back to the heights that yielded silver and bronze medals behind Alistair at two Olympics, and a world title in 2012.
Like his elder brother he animated the cycle leg with attacks, but once it came to the 10km finale on foot he was struck by a stomach ailment and fell down the field to 35th.
“I’m really upset,” said the 29-year-old. “I was feeling really good the first half of the race, but then I started running and my stomach started hurting. I don’t know if it was a stomach bug.
“My training has gone really well, I felt fitter than I have for a number of years. I actually felt at the start of the run I had a good chance of winning the race, but it quickly turned into survival mode.
“I’ve been so far off where I have been in the last few races that I need to go back and find out what’s wrong.
“Something must be wrong, and I have to find out what that is to compete at the top level again.
“I’ll talk to my coaches, the people I trust and speak to them and see where I go from there. If that means taking time off then so be it, but I just need to get things right, because that was awful.
“I’m 100 per cent committed for Tokyo. It wasn’t a fast run that won that race, so if I get back to where I should be I should be very competitive.”
For Birtwhistle, victory felt like a long time coming.
The Australian has been knocking on the door for the last couple of years, but had not expected to break it down in Leeds, a course for which the swim in Roundhay Park sets up so much.
“It’s a course set up for a strong swim-bike and usually me the swim is hit or miss for me said the 24-year-old, who has been based in Leeds since the last World Series race in Yokohama three weeks ago. “[Yesterday] I was thankful it was good and I was in the mix from the start.
“Maybe it’s the familiar roads, the familiar temperatures that helped a little bit. But everything came together and I kept fighting and digging deep.”
First Briton home was Tom Bishop, the long-time domestique of the Brownlee brothers who was sixth here last year.
“I gave it everything I had,” said the 27-year-old, who is based in Leeds at the British Triathlon high performance centre.
“That was one of the strongest fields we’ve seen in Leeds.”
Londoner Alex Yee is one to watch in the future.
The 21-year-old is also based in Leeds and his strong running earned him a 15th-place finish in his first year as a senior.