So they caught him in the end, Mo Farah losing his last championship race on the track inside a packed London Olympic Stadium, beaten into second place after a savagely competitive 5,000 metres final.
That Farah gave it his all is undeniable: likewise that Muktar Edris of Ethiopia was the better runner on the night, getting in front of Farah on the last lap and simply never surrendering.
Indeed, Farah was only fourth coming into the homestretch and chased down Edris fast with the line approaching; just not fast enough, Edris winning in 13:32.79, slow by championship standards but in tactical execution perfectly impressive.
Farah was less than a second back in 13:33.22, the Kenyan-born America Paul Chelimo winning bronze in 13:33.30. Clearly spent by his effort, Farah fell to the track, buried his head in his hands, hardly believing himself he'd been beaten in a championship race on the track for the first time in six years.
“Tactically, they worked as a team,” said Farah. “With the Kenyan and Ethiopians anything is possible.
"It's been amazing. It's been a long journey but it's been incredible,” Farah added. “It doesn't quite sink in until you compete here and cross the line – I had a couple of minutes to myself – that this is it.
"To be honest with you it takes so much out of me. It's not an excuse, but it took a lot more out of me than I realised. Tactically, I was trying to cover every move. They had the game plan: one of them was going to sacrifice themselves. That's what they did tonight, and the better man won on the day. I gave it all, I didn't have a single bit left at the end.”
Edris is certainly no slouch - the fastest in the world this year with his 12:55.23. And so he denied Farah a fifth consecutive distance running double, ending his hopes of adding a second gold in London to go with the 10,000m he won eight days ago: Farah, with six gold medals, is still the single most decorated athlete in British athletics history.
But no other athlete - not Haile Gebrselassie, not Kenenisa Bekele - has won four gold medals in the 5,000m at the World Championships; nor indeed a fourth medal of any colour. Perhaps this was a step too far into greatness, even for an athlete like Farah.
As a race it started fast, slowed to the proverbial crawl: Farah first hit the front with seven and a half laps to run, unusual for him, determined to dictate the pace than follow it.
Then came surge after counter surge, Farah riding on the back of each one. Five laps to go, Chelimo went again, then the Australian Patrick Tiernan, briefly opening a 10 metre gap, the tension rising all the time.
Into the last 800m however and they ate Tiernan up, though the truth is Farah never looked entirely comfortable: they hit the bell in 12:40.17, and Farah was chasing all the way down the backstretch, unable to get himself in front when he either wanted to or needed to.
In a strange way, however, this defeat might well offer some brief respite from the shadow of doping and some of the hard questions that have come with his previously unbreakable displays of championship distance running.
Now aged 34, old though certainly not ancient, Farah had only lost one of his 23 races at 5,000m since moving to Alberto Salazar, still under investigation by the US Anti-Doping Agency into his methods of training at the Nike Oregon Project.
He hadn’t lost a major championship race on the track since the 2011 World Championships in Daegu, South Korea, winning silver in the 10,000m, then came back to win the 5,000m later in the week, before successfully doubling in the 2013 World Championships in Moscow, and again two years ago in Beijing.
Only tonight he did lose, something about the way he fell to the track afterwards making him look quite human after all. Last Friday night, he produced another bold if not ballsy display in the 10,000m, riding each wave of surge and counter surge with utter fearlessness: he very nearly fell over himself too with 300m to run - yet held his nerve and ultimately devastating kick to win in 26:49.53, the fastest time in the world this year.
That effort may well have taken more out of him that Farah himself had realised.
Earlier, Sally Pearson produced one of the great comebacks in World Championship history, winning the 100m hurdles five years after the Australian women won Olympic title on this track, and after two years of crippling injuries which threatened her career.
Pearson delivered the perfect championship performance too, her 12.59 seconds run from the front and enough to hold off the American Dawn Harper Nelson, with Germany's Pamela Dutkiewicz beating world record holder Kendra Harrison for the bronze.
“That was bloody hard, it’s so incredible, crazy,” said Pearson, who missed the 2015 World Championships and feared she might have to have her lower arm amputated after she broke it in a traumatic fall at the Rome
For Farah, there will be no comeback on the track, as he now moves up the marathon looking to extend his gold medal haul. That he finishes with silver on the track clearly wasn’t the farewell he had planned.
