Months after he feared his tennis career might be over, Juan Martin Del Potro stunned Rafael Nadal to reach the gold medal match in Rio and a meeting with defending champion Andy Murray.
The gentle Argentinian with the monster forehand lay flat on the court after pulling off a 5-7 6-4 7-6 (7/5) victory over Nadal in a thrilling three-hour contest.
The crowds at the tennis, in common with many other venues, have been largely disappointing but this was a gladiatorial match played in a Davis Cup-style din.
Having battled back from one serious wrist injury to reach the top of the game again, with arguably the highlight being his Olympic bronze medal in 2012, Del Potro was forced away from the sport once more in 2014.
Three operations on his left wrist later, the former US Open champion was left wondering whether he would ever make it back.
But he has tentatively been making positive strides and this week he has shown tennis just what it has been missing.
It began with a superb upset of world number one Novak Djokovic, which left both men in tears, and will end with an Olympic gold medal if he can beat Murray on Sunday.
Nadal came from a break down to take the opening set but Del Potro struck again early in the second and maintained his advantage.
The third was a rollercoaster ride for both men and the crowd, with umpire James Keothavong fighting to keep some semblance of order.
Del Potro looked like he had made the crucial breakthrough when he served for the match at 5-4, only for Nadal to break back to love, whipping a forehand winner on the final point and leaping in the air.
In London in 2012, Del Potro played another epic semi-final against Roger Federer, which the Swiss finally won 19-17 in the deciding set.
Third-set tie-breaks were introduced for these Games and Del Potro was never behind, clinching victory on his second match point when Nadal hit a forehand wide.
It marked a first ever singles defeat for Nadal at the Olympics but Rio had already far exceeded the Beijing champion’s expectations.
Having been unsure whether he would even play after more than two months out with his own wrist injury, the 30-year-old has now played 11 matches and won gold with Marc Lopez in the doubles.
He will attempt to add a bronze when he plays Kei Nishikori on Sunday.