They might have handed the gold medal to super heavyweight Aleksandr Karelin before the 2000 Sydney Olympics. Photo / Getty Images.
Czech Ester Ledecka has caused one of the most amazing Olympic shocks in South Korea, with her win in the Super G on borrowed skis.
We check out five famous Olympic upsets, from the summer and winter Games.
Rulon Gardner (USA) The American Greco-Roman wrestler's life should be a movie, a story which began when he upset the greatest Olympic grappler of them all.
They might have handed the gold medal to super heavyweight Aleksandr Karelin before the 2000 Sydney Olympics, so dominant was the triple gold medal winning Russian Bear.
He'd never even given up a point in the six years leading up to those Games.
But Wyoming's Gardner won the gold medal match, the shocked judges actually reviewing the moment in which Gardner scored the only point when Karelin briefly lost his grip.
Gardner then survived a mandatory over time period because the scoring was so low.
Karelin, whose international record finished at 887 - 2, was given various titles including "probably the toughest man who ever lived" by writers. He could actually send opponents flying.
In contrast, it was a surprise to even see Gardner in the final. He was the dog tucker who barked, producing astounding defence against a dominant opponent and survived passivity calls against him.
Gardner celebrated with a cartwheel, but his life spun in unfortunate directions.
He needed a toe amputated after getting lost in a forest during winter, was in a motorcycle and plane crash, turned up on a fat-busting reality show, and got into millions of dollars of debt.
Gardner won bronze in Athens four years later but lost both medals due to the bankruptcy. He's still got his toe though, kept in a bottle of formaldehyde in the fridge.
"I don't have all this money people think Olympic athletes have," he once said.
Billy Mills (USA) Mills was the subject of a film called Running Brave, about the way he overcame many things including low blood sugar levels and the Australian record setting legend Ron Clarke to win the 10,000m gold medal at the 1964 Games in Tokyo.
Mills, from the Ogala Sioux tribe, was an orphan by the age of 12. He found an early talent for running although reports say he suffered verbal abuse from a college coach. His upbringing has been described as impoverished, in a family of 15.
His father had told young Billy he would have the "wings of an eagle". Spotting exactly that on the shirt of a struggling German runner, US Marine Mills flew past Clarke and pace setting Tunisian Mohammed Gammoudi in the final 80-metres, taking advantage of the drier outside lane.
A Japanese official ran up to Mills — "a complete unknown" — asking: "Who are you? who are you?"
Mills was not only the gold medallist but the new Olympic record holder, exceeding his previous best by a staggering 50 seconds. His rapid improvement has been linked to the Arthur Lydiard distance method, presented to him by an Australian athlete.
He has spent much of his life trying to inspire and assist native American kids, and being an activist for Native American rights.
Emil Zatopek (Czechoslovakia) Someone as famous as Zatopek is a very unlikely member of an Olympic upset list. But winning the marathon gold medal at the 1952 Helsinki Games was a performance beyond belief, his third event in eight days after he had won gold in the 5000 and 10,000 metres.
Added to that, he had never run a marathon before, and only decided to turn up at the final hour. He joked that his wife Dana's win in the javelin has provoked his entry.
"I decided that the ratio of medals in the Zatopek household was insufficiently weighted in my favour," he reportedly said.
The hot favourite was Brit Jim Peters, and when Zatopek caught and engaged him after about 15km, Peters claimed the pace wasn't quick enough. Zatopek responded with a burst which left Peters with cramps, and he quit.
After winning comfortably, Zatopek described the marathon as boring and he ran just one more.
Zatopek's running style was so awkward that he looked in constant agony. The famous American sports writer Red Smith reckoned he "ran like a man with a noose around his neck".
Zatopek's character, eccentricities, warmth and generosity were legendary. He was revered by one and all, and made incredibly brave stands against the Communists in his country. He was exiled for his troubles, and later life was not always kind.
He may be the greatest Olympian of them all, when everything is taken into account, and his 1952 marathon gold is just part of an incredible life.
Zatopek said: "I try to lead a normal life...Sportsmen are like children, they don't know anything about life."
Zatopek passed away in 2000, but Dana — aged 95 — still lives in Prague.
"The most beautiful thing that I remember was the day after the races were finished," she said a couple of years ago. "Everything was so beautiful...sitting by the lake afterwards, it was like a fairy tale."
Steven Bradbury (Australia) Bradbury emerged triumphant in truly wacky circumstances, from the 1000m speed skating final at Salt Lake City in 2002. He was the first southern hemisphere athlete to win a Winter Olympics gold.
Bradbury, a massive outsider, was trailing the five-man field when a crash took out the rest just before the finish line. America's Apolo Ohno, badly cut, crawled across the line to take silver.
It was Bradbury's fourth Olympics. He had gone to Salt Lake City to exorcise "demons" having almost died after being impaled on a rival's skates in 1994. He also broke his neck in training 18 months before those 2002 Games.
"My best chance (in the semifinal) was to get on the ice and stay out the way and I figured there was no reason to change my tactics for the final," he said.
After gliding to gold, he "wasn't sure if I should put my arms up in the air in celebration or go and hide in the corner".
He wrote in the Players Voice this month: "If I was to do it again today, I wouldn't stand up on the top of the podium. I'd just make the guy come around to the side and put it on me and stay off the podium."
Sarah Hughes (USA) The 16-year-old figure skater did the near-impossible, rising from fourth after the short programme to claim gold with a blitz of triple jumps as famous rivals lost the plot.
Compatriot Michelle Kwan and Russian Irina Slutskaya went from gold medal prospects to dejected losers in one of the great Olympic shocks.
"I think this just shows, don't make predictions in skating because who knows,'' Hughes said.
She pointed out that while the media and public might not see an athlete as a favourite, they still operated under self-imposed pressure and expectations.
Years later, she reflected in the New York Times: "I'm astounded by what I actually accomplished. I trained for those four minutes, but afterward, I couldn't believe what I did. I know I did the two triple-triples. I remember them well. I nailed each one. But there were so many things I did. I forgot about all those things."