He is the first amputee athlete to compete at an able-bodied world championships. In Sunday's heat, Pistorius had run 45.39 seconds, the second-fastest time ever for him. But he was only 22nd among 24 runners in the semifinals Monday.

"I would really have liked to have performed better tonight. My goal was to make the semi-final and I did that," Pistorius said.

"It's been a great experience. Even if I had run faster tonight, I wouldn't have made the final."

Pistorius' personal best is 45.07, which he ran last month to qualify for the Daegu championships. That time would have put him in the final Monday, but he had earlier said it would take a lot of work for him to come close to the mark.

He still said he is taking a lot from his first world championships.

"It has been a dream absolutely come true," Pistorius said.

"This is the championship I have worked for many years. It's been a massive blessing."

Pistorius, 24, is dubbed "Blade Runner" for his carbon fiber artificial limbs. He had both legs amputated below the knee when he was 11 months old because of a congenital condition that caused him to be born without his lower leg bones.

His presence in Daegu has once again sparked the controversy over his blades and whether they give him an edge over others.

In 2008, the International Association of Athletics Federations

(IAAF) banned him from its competitions, citing advantages his legs helped him enjoy over able-bodied athletes. The Court of Arbitration for Sport later overruled the IAAF decision and made Pistorius eligible for competitions.

Pistorius ultimately came up short of the qualifying time for the Beijing Olympics, and he is hoping to make the London Olympics next year. But the IAAF recently said it has the power to reevaluate the situation and determine whether Pistorius'

prosthetic limbs remain within the rules.

Pistorius may also enter the 4x400ｍ relay heat on Thursday.