Competition at the Beijing Paralympics got underway Sunday as the United States and Britain won four gold medals apiece for an early lead in the race for most medals.

China captured three golds but led the overall medal count with 13, against the Amercians' nine and Britain's seven.

Du Jianping earned the host country's first gold at the Games when he won the men's 100m freestyle in the S3 class in a world record time of one minute 42.95 seconds.

"I got choked in the beginning. I breathed on the right side and saw that the Ukrainian swimmer was catching up, which made me a little nervous," said the 25-year-old Du. "I held my breath and swam my strokes as fast as I could with nothing else in my mind but a gold medal."

Cui Na and Guo Huaping then added a double gold in judo for China, who topped the medals table at the Athens Paralympics in 2004 with 63 golds and is expected to dominate again on home soil.

The Americans continued their dominance in swimming by winning four gold medals at the Water Cube, but South Africa's Natalie du Toit was the biggest star.

The 24-year-old amputee, who competed in the 10-kilometer open-water swim at last month's Olympics and finished 16th among 25 competitors, began her quest with a bang for five gold medals at the Paralympics when she broke her own world record to win the S9 women's 100m butterfly.

Du Toit, who lost her lower left leg in a motorcycle accident in 2001, clocked one minute 06.74 seconds, chopping 0.05 seconds off the previous mark she set in 2006.

Du Toit and Polish table tennis player Natalia Partyka are the only athletes in Beijing who will appear in both the Olympics and Paralympics.