(CNN) -- South Africa's "Blade Runner" Oscar Pistorius is still struggling to qualify for the Commonwealth Games despite smashing his own Paralympic record in Britain on Saturday.

The 23-year-old, a double-amputee, triumphed at the 400 meters T44 event at London's Crystal Palace, setting a new leading time of 47.03 seconds.

Pistorius, who won the right to compete against able-bodied athletes in 2008, was a clear winner in the Paralympics-ratified race as he finished 4.61 seconds ahead of British runner-up Ian Jones.

However, with South Africa due to name its team for the October 3-14 Games in Delhi later this month, time is running out for him to attain the qualifying standard of 45.95.

Pistorius did not qualify for the 2008 Olympics but set his previous world 400m record of 47.49 in winning gold at the Paralympics in Beijing.

He ran in a 400m B race in London on Friday night, but the damp conditions were unsuited to his carbon-fiber prosthetic limbs and he finished outside of the qualifying time with 46.93 as he placed seventh.

Meanwhile, American runner Jeremy Wariner clinched his fifth consecutive Diamond League victory this season when he won the 400m in London on Saturday.

The triple Olympic gold medal winner came home in 44.67 to head off Jamaicans Jermaine Gonzales (44.80) and Ricardo Chambers (45.18).

His compatriot Allyson Felix followed up her 200m win on Friday by claiming a double as she triumphed in the 400m from Russia's European champion Tatyna Firova and fellow U.S. runner Debbie Dunn.

Marshevet Myers won the women's 100m from fellow American Carmelita Jeter, and their compatriot Wallace Spearmon won the men's event.

David Oliver romped to his fifth victory of the series in the 110m hurdles to seal a successful night for U.S. athletes.