As the half-time siren rung out around the Stade de France during the women’s rugby sevens semi-final, Australia could hardly have looked more comfortable.

New Zealand had breezed through to the gold medal match just minutes before with a comfortable win over the US, and now Australia was well on track to hold up its end of the bargain in setting up the dream final.

The Aussies had been brilliant through the first two days of competition and picked up right where they left off in the first half against Canada. Everything was going to plan.

Fifteen minutes later, shell-shocked Australians collapsed to their knees and wept. Only a couple of hours later, it was nearly a mirror image.

From romping towards the gold medal this team has been fixated on for years, suddenly the Australians would be going home empty-handed. Canada overran them in the semi-final, the US sucker-punched them in the bronze medal game.

Coach Tim Walsh and his squad will spend the next four years making sense of just how it all fell apart so quickly.

Eventually they will identify a small handful of errors across the two games, minuscule moments in a sport defined by them, which cost them so dearly.

The first half against Canada was just about perfect from Australia’s perspective, with tries to tournament stand-out Maddison Levi and Sariah Paki setting up a 12-0 lead that so easily could have been more.

The Canadians barely saw the ball, and certainly hadn’t seen their own attacking half when the siren went. At that precise moment Australia conceded a penalty for not releasing the ball, and for only a split second lost concentration.

In that pause, Canada’s Charity Williams burst through the idle defence to score a try her team had not yet threatened. The Canadians were back in the game from nowhere.

In the second half, the Australians couldn’t get their hands on it. Canada was relentless in attack and refused to make an error, and eventually took a lead through Asia Hogan-Rochester’s try and Olivia Apps’s conversion.

On the back foot for nearly the first time all tournament, Australia needed to calm things down before offering its response. But almost immediately after taking possession from the kick off, Teagan Levi inexplicably fumbled a pass, knocked the ball on and surrendered the initiative again.

Australia couldn’t recover. Logan Piper’s try made sure of what was described on commentary as “the biggest shock in the history of women’s rugby sevens”.

In most sports, after a loss like that the players would have days or weeks to process their heartbreak before facing up to the next challenge. The Australians here had about three hours before they had to take to the field again with an Olympic medal on the line. 

Facing a US team for whom any sevens medal would represent the biggest breakthrough for the sport in the country’s history, perhaps Australia was just a little lacking in the motivation stakes.

And yet, the Aussies performed professionally. They took a lead through Maddison Levi’s 13th try of the tournament and looked in control.

A yellow card to Teagan Levi midway through the first half had Australia scrambling, but its defensive line held on bravely until her two-minute time out had passed, at which point it promptly coughed up a try to Alev Kelter.

The second half against the US was tense and tight, a stop-start encounter that neither side could really dominate. Paki blew a glorious chance to give Australia a lead when she spilled a pass on her way through to an unimpeded try, but even still it looked like Australia would get away with the bronze.

With the best play of the match, Australia won the ball back at a scrum against the feed and set Teagan Levi away. She was able to combine with sister Maddison who crossed again — make that 14 tries — for what looked every bit like a match-winning play.

With a five-point lead, Australia went long from the kick off. There was less than a minute on the clock and with the play at the other end of the field hopes of a US miracle were fading fast.

Until Alex Sedrick sized up Teagan Levi and ran directly at her. Teagan had a grip on Sedrick’s upper body if only for a moment, before the force of the 160cm bulldozer overpowered her.

Sedrick was gone, under the uprights and in. The conversion was a formality, something the Australian knew as they broke down in tears before the game was even officially over.

The Australian women woke up this morning totally convinced by the end of the day, they would be Olympic gold medallists. Instead the day became a nightmare, a cruel conclusion to an excellent campaign that started long before these Games began.

“It’s a game of moments. And there’s probably a few things we would’ve loved to do differently but we can’t take that back,” captain Charlotte Caslick conceded.

“It sucks. We played our hearts out that’s the beauty of sevens and sport — that’s why we play it.”

Canada and the US made their share of mistakes in those fateful matches, but none were punished like Australia’s. Great players made small errors, and on this occasion those small errors had significant consequences.

A couple of fumbles, a momentary lapse of focus, a missed tackle. That was the difference.

Australia’s women’s rugby sevens side lost no admirers in Paris, and surely won some new fans, all while reminding us that sport doesn’t always have to be fair.