Lin Dan of China
claimed his second successive Olympic gold
with a 15-21 21-10 21-19 defeat of Lee Chong Wei of Malaysia in a classic final.
The left-handed world champion and world number one, 28, lost the first game to a more sprightly opponent, but was able to turn the tables.
He forced Lee, 29, who was roared on by a raucous Malaysian following, into a series of unforced errors.
The final game was a 40-point thriller and seals Lin's all-time great status.
"You couldn't have asked for any more from Lee Chong Wei. He just came up against Lin Dan again. I wish they could give a gold medal to both of them. It's thoroughly deserved for Lin Dan."
There were high hopes going into this game with both players highly-rated and a catalogue of classic finals of the past shared between them. This match did not disappoint.
The final started at a breathless pace, the lead in the first game changing five times inside the first 13 points.
But Lee found the tactics and reactions to grasp a lead then extend it, overpowering a surprisingly error-prone Lin 21-15 after just 26 minutes.
The second game contained a complete role reversal as a more powerful and dominant Lin bossed the court.
Lin found joy at the net, with drop shots forcing his Malaysian opponent to respond with lofted defensive replies, which Lin could smash for success.
Lin was so dominant in the second game that Lee elected to effectively concede, losing 21-10 but conserving energy for the decider.
It was a tight affair, with the lead again changing multiple times. But Lin proved the stronger and prevailed, wheeling away in celebration at the finish with Lin, who will not compete at the next Olympics in Rio, seemingly inconsolable.
For the Chinese pin-up gold in London made him the first man to win successive men's singles Olympic badminton titles.
The bronze medal was claimed by another Chinese player, Chen Long.