Of all the tales of unexpected sporting shocks – the sudden physical crumbling, the slow tactical misjudgment – not many can compare to what unfolded in Tokyo this weekend 25 years ago. Not when one of those involved can truly say they never saw it coming.

No, it wasn’t just Mike Tyson being knocked out by James ‘Buster’ Douglas at the Tokyo Dome: it was also John Treacy losing to Takeyuki Nakayama in the Tokyo Marathon. Because Treacy, for one, never once expected he’d lost, even when reaching the finish line.

Tyson’s defeat was certainly shocking – although that’s not saying no one saw it coming. At 23, he was already 37-0 in professional fights, including 33 KOs, the undisputed heavyweight champion of the world. Douglas was the 42/1 underdog, partly because his preparations were interrupted by the death of his mother 23 days before. And then he split with his father and coach.

And yet in Tyson: The Movie, the fight preparations of Tyson are also questioned – especially given his recent divorce from actress Robin Givens: "I lost a lot of desire in my fighting," says Tyson. "And when I went to Japan, I had a lot of women in my room... matter of fact, when I was training one of my sparring partners dropped me. That's how serious I was training."

Heavyweight history

Speaking to Newstalk’s Off The Ball this week, Ron Borges of

The Boston Herald

– one of only six American journalists sent to Tokyo in February 1990 – recalled a meeting with Douglas, on the eve of the fight. “What can Tyson do to me that the world hasn’t done?” he told Borges, who then immediately expected Douglas to win. After 10 rounds and the knockout count, everyone else saw it coming too, and the rest is heavyweight history.

When Treacy lined up for the Tokyo Marathon the following morning, news of Tyson’s defeat was still breaking around the world, although the city itself was concerned with bigger things: no country is more obsessed with marathon running than Japan, and the Tokyo Marathon was and still is a spectacle unlike any other. Millions of people lined the 26.2-mile route, which started and finished in the National Olympic Stadium, and although it was unseasonably warm for February, Treacy, unlike Tyson, had come perfectly prepared.

Six years after his silver medal in the LA Olympic Marathon, he was still craving the big city win – having finishing third in Boston (twice) and New York. With then world record holder Belayneh Dinsamo from Ethiopia also lining up (having run 2:06:50 in Rotterdam in 1988), Treacy wouldn’t have it all his own way, so he sat back a little in the opening miles, eased his way to the front around halfway, then made a decisive surge at 21 miles. With that, he opened a gap on Dinsamo, and still felt full of running as the Olympic Stadium came back into view. Treacy was out on his own, two race clocks and a large press truck alongside him, comfortably cornering the sharp bends between the Tokyo skyscrapers, as the finish approached. In typical Japanese fashion, the crowds were furiously waving flags yet otherwise mostly silent, and Treacy made several glances over this shoulder, just to confirm no one else was close.

With that he ran into the Olympic Stadium, a final lap of the track, before crossing the line in 2:11:23, briefly raising his arms in the moment of triumph. Then Treacy stepped onto the infield, to be greeted by his agent Kim McDonald.

Sitting down

“Another half mile, John, and you had him,” he said.

What?

“He was dying.”

Who?

With that McDonald pointed towards Nakayama, the Japanese runner, sitting down on the infield, a few metres away. No one saw it coming, but Nakayama had raced clear from the start, quickly opened a half-mile lead, and somehow kept himself in front until the finish, winning in 2:10:57. Treacy, even though he finished just 26 seconds behind, never once saw him, the TV coverage of the race proving it, as they were never once in the same shot.

Treacy eventually got his big city marathon win, in Los Angeles in 1992, and also Dublin, in 1993, and as unceremonious as Tokyo proved, it may well be the ultimate example of the unexpected sporting shock. If Ireland end up losing to France at the Aviva Stadium this evening, despite being Six Nations tournament favourites, at full strength and ranked number three in the world, no one can say for sure they didn’t see it coming – not when they’re playing the most wildly unpredictable team in world rugby. It may be a sudden physical crumbling, or even a slow tactical misjudgment, but at least the team won’t be walking off the field thinking they had won, only to be told the opposite.

Twenty-five years after his 2:11:23 in Tokyo, and 27 years after his Irish record of 2:09:15 in Boston, it will be certainly be a sporting shock if any Irish athlete preparing for Rio runs quicker than Treacy, because I, for one, can’t see it coming. Nothing should be so unexpected.