Despite a slow start on a wet track, the South African won the most difficult of his three races, clocking 11.17 on Tuesday to take gold at 100 metres. American Jerome Singleton was just behind with 11.20, and Brian Frasure of the United States got bronze with 11.50.
Pistorius will be a strong favorite to win the 200 and 400.
The double amputee, known as the "Blade Runner" because of the prosthetic legs he races on, won a legal battle in May for the right to run in the Olympics. However, subsequently he failed to meet the qualifying time standard.
"I had a tough start and a slow first 30 metres," Pistorius said of the 100. "I really just pulled out all the stops."
Pistorius still has his sights set on qualifying for the Olympics.
"I'm looking forward to London 2012," he said.
Pistorius' medal event was one of 20 on the track on Tuesday in the third day of competition. Swimming offered 16 with 7 in cycling and two dozen more in shooting, judo, equestrian, and powerlifting.
American Erin Popovich won her third gold medal in the pool, taking the 100 breaststroke for her disability class. She has also won gold in the 200 IM and the 100 freestyle.
Popovich won seven gold medals in Athens. She will go for only six this time as her other gold in 2004 came in a relay, which has been cut from the program.
Through three days, China leads with 16 gold and 53 overall. Britain is No. 2 with 14 gold and 32 overall. The United States is No. 3 with 10 gold and 26 overall.
Away from the venues, the Paralympics had its first athlete banned for failing a doping test.
Pakistani powerlifter Naveed Ahmed Butt tested positive for the steroid methandienone metabolites, the International Paralympic Committee said in a statement Tuesday.The urine sample was taken Sept. 4, two days before the opening ceremony.
Butt was handed a two-year ban and had his accreditation cancelled.
