Rosie Ruiz joined the 1980 Boston Marathon from the crowd, near the finish line, ahead of all the other femail runners and was declared the winner. Her time of 2:31:56 was initially declared the fastest female time in Boston Marathon history as well as the third-fastest female time ever recorded in any marathon.
Rosie was stripped of her title 8 days after the race after overwhelming evidence amassed of her cheating. The fact that it took that long was surprising, given all the indications that she could not have won. Her time was more than 25 minutes ahead of her reported time in the New York City Marathon six months earlier, which qualified her to run the Boston Marathon, which she had also not actually run! She didn't seem out of breath or sweating at the finish line and didn't look anything like a world class athlete. It was also clear from her finish line interview that she handn't a clue about marathons. Amazing.