Brazil's Alan Oliveira (R) is congratulated by South Africa's Oscar Pistorius after winning the men's 200m T44 classification at the Olympic Stadium during the London 2012 Paralympic Games, Sept 2, 2012. [Photo/Agencies]

LONDON - Brazil's Alan Fonteles Cardoso Oliveira upset defending champion Oscar Pistorius to win the men's 200 meters title at the London Paralympic Games on Sunday.

The South African, who won gold in the event four years ago in Beijing, complained vociferously about the length of his opponent's blades after he was beaten into the second.

Pistorius streaked into an early lead and was almost ten meters ahead as the athletes came into the closing straight. The Brazilian, however, struck back in the closing stages to eat up the ground and surge past Pistorius in the final few meters.

The underdog Oliveira finished with a time of 21.45 seconds, seven tenths of a second ahead of Pistorius with American Blake Leeper in third.

The result left Pistorius seething about his opponent's prosthetic blades, which he claimed were too long.

"This is a really strong race of mine, and as I said in the mixed zone, the size of some of the other guys' legs are unbelievably long," Pistorius told Britain's Channel 4.

"Not taking anything away from Alan, he's a great athlete, but the guys who do the measuring in the courtrooms, some of these guys are a lot taller and you can't compete for stride length.

"We're not racing a fair race. The International Paralympic Committee (IPC) have the regulations, but the regulations allow the athletes to make themselves unbelievably high. We tried to address the issue in the weeks leading up to this, but it fell on deaf ears.

"The guys are running ridiculous times. Alan is a great athlete, but I run just over 10 meters per second, so I don't know how you can come back from eight meters behind after 100m to win. It's ridiculous."

Brazil's Alan Oliveira (L) celebrates in front of South Africa's Oscar Pistorius after winning the men's 200m T44 classification at the Olympic Stadium during the London 2012 Paralympic Games, Sept 2, 2012. [Photo/Agencies]

Oliveira's winning time was still 0.15 seconds slower than the world record set by Pistorius in Saturday's heat.

The 25-year-old, dubbed the "Blade Runner", was defending the 100m, 200m and 400m Olympic titles he won in Beijing four years ago. Last month, he became the first double amputee to run in the Olympics and made the 400 meters semifinals.

"The length of my blades are alright because I went through all the procedures with the referees," Oliveira said. "Once I came inside the track, it had all been cleared up and I think Pistorius also knows that.

"I have been using them for a whole month; just the same blades, according to the IPC rules...

"I am very happy, I have written my story on the Paralympic wall."