Paralympics: 'Blade Runner' Oscar Pistorius begins gold quest

"Blade Runner" Oscar Pistorius begins his quest to retain his three Paralympic sprint titles on Saturday but he could be eclipsed by a lightning-quick Irishman, as a controversial showdown beckoned in the pool.

The South African sprinter, who earned his nickname as he competes on carbon fibre prosthetics, lines up in the heats for the T44 200m in London, just weeks after becoming the first double-amputee to compete in the Olympics.

But while the 25-year-old has become a household name across the world, another defending Paralympic champion has staked his claim to be king of the track -- and the new face of the competition.

Jason Smyth, of Ireland, blitzed the field in the T13 100m heat late on Friday, lowering the world record to 10.54secs and securing a place in the final on Saturday night, just before Pistorius begins his campaign.

Smyth, who is visually impaired and like Pistorius also runs in non-disabled races, trains in Florida with US sprint star Tyson Gay, who is the second-fastest man in history over the 100m behind Jamaica's Usain Bolt.

"I've been based out there for the last three years so (I'm) pretty much doing exactly what those boys are doing, I'm part of the group," he told reporters.

"I've come along a way, I've learned a lot and I've got quicker and quicker, so just to be in that environment with the second quickest man ever is great."

Smyth has run 10.22secs -- 0.27secs quicker that the non-disabled women's 100m record set by Florence Griffith-Joyner in 1988 -- but his time was not recognised as it was not in an International Paralympic Committee-sanctioned event.

Meanwhile in the pool, US swim team poster girl Victoria Arlen, who holds the women's S6 100m and 400m freestyle world record, eased through her heat in the longer race to face Britain's defending Paralympic champion Ellie Simmonds.