Those fans, along with Kerr and Ingebrigtsen, had not counted on Hocker crashing the party.
At the end of a ferociously fast race, in which Ingebrigtsen set the pace with a 54.9-second opening lap as the two heavyweights fixated on destroying each other, it was Hocker who had the legs to push on.
Sixth in Tokyo three years ago and seventh at last year’s worlds, this was not an outcome anyone expected, with all the build-up centred on the rivalry which had seen the men’s 1500m emerge as the unmissable athletics final at Paris 2024.
Lining up with a personal best of 3:30.59, the 23-year-old Hocker improved upon it by almost three seconds as leader Ingebrigtsen turned the screw in trademark fashion.
Against the odds, the American seized the biggest opportunity of his fledgling career, raising his arms aloft as he crossed the line to the astonishment of all, with Kerr and Ingebrigtsen in his rear-view.
Team GB’s Neil Gourley finished 10th, in a time of 3:30.88.
“Of course, I was looking for that gold medal, but it’s a better medal than I got three years ago,” Kerr said.
“It was fast, this crowd was absolutely electric. We went for it, we promised a fast and great race, and that was the result.
“I executed the fastest that I’ve ever run by almost two seconds. It wasn’t enough today. That’s sport. I’m very proud of myself. I left no stones unturned and that’s the result today.”
Ingebrigtsen later admitted his fast start had not been intentional, and ultimately proved his downfall.
“I opened with a 54-second lap. That wasn’t the plan at all. It was at least two seconds too fast,” said Ingebrigtsen, whose winter training was disrupted by an Achilles injury.
“I was thinking about slowing down, but the next lap was almost the same speed. I ruined it for myself by going way too hard.”