Oscar Pistorius was dethroned as king of the blade runners at a shocked Olympic Stadium by Brazilian Alan.
The South African looked to have the gold in the bag as he came off the bend in the lead and raced clear down the home straight, but Alan reeled him in to take gold in the T44 200 metres in 21.45 seconds. Pistorius, a Paralympic icon, came home in second in 21.52secs with stunned quiet from the 80,000 spectators greeting the result.
The South African made it clear he did not feel he was running on a level playing field, with some of his competitors' running blades longer than he believes they ought to be.
"As I said yesterday, the IPC don't want to listen," he told Channel 4. "The guys' legs are unbelievably long. Not taking away from Alan's performance, he's a great athlete, but these guys are a lot taller and you can't compete [with the] stride length. You saw how far he came back. We aren't racing a fair race. I gave it my best.
"The IPC have their regulations. The regulations [allow] that athletes can make themselves unbelievably high. We've tried to address the issue with them in the weeks up to this and it's just been falling on deaf ears.
"You saw Blake Leeper when the guy came down literally overnight, made his blades longer. His knee height is like four inches higher than it should be. The guys are just running ridiculous times and they're able to do so.
"I think Alan's a great athlete but...I run just over 10 metres per second, I don't know how you can come back, watching the replay, from eight metres behind on the 100 to win. It's absolutely ridiculous."
Speaking through an interpreter, Alan told Channel 4: "The length of my blades is all right, I went through all the procedures with the referees. Once I come inside the track it's because it's all been cleared up and I believe Pistorius also knows that."
Asked if he had changed the length of his blades between the semi and the final, Alan replied: "No. Since the first time I put them on they've been following the IPC rules and I've been using them already for a whole month, just the same blades."
A spokesman for the International Paralympic Committee said: "There is a rule in place regarding the length of the blades which is determined by a formula based on the height and dynamics of the athlete. All athletes were measured today prior to competition by a classifier and all were approved for competition."