Daegu - National 400m hurdles record holder LJ van Zyl secured South Africa's first medal, bagging bronze at the World Athletics Championships in Daegu, South Korea on Thursday.

Van Zyl, starting the final in lane eight after a poor qualifying time, was well placed off the top bend, but struggled over the last 40 metres.

American Angelo Taylor, however, tied up over the last hurdle and Van Zyl sneaked home in third in 48.80 seconds.

David Greene of Great Britain won gold in 48.26, with Javier Culson of the United States taking second in 48.44.

Former South African champion Cornel Fredericks, 21, finished strongly to place fifth in 49.12.

Ruben Ramolefi trailed home in a disappointing 13th position in the men's 3 00m steeplechase final.

Ramolefi started well, taking up the early pace, but dropped off the lead group midway through the race to finish in 8:30.47 -- more than 19 seconds slower than the national record he set in the heats earlier in the week.

Oscar Pistorius and Caster Semenya had earlier stolen the show in the morning session as the SA team produced superb performances in qualifying rounds.

Double amputee Pistorius, who reached the semifinals of the men's 400m sprint earlier in the week, formed part of the quartet that set a national record in the men's 4X400m relay heats.

Pistorius joined Ofentse Mogawane, Willem de Beer and Shane Victor as they finished third in their heat behind favourites the United States and Jamaica.

The SA quartet clocked 2:59.21 to break the 12-year-old national best, set at the 1999 global championships in Seville, Spain, by 0.99 seconds.

"I'm very happy with my leg and I hope the team is happy with it as well," Pistorius said.

"Today, that was the best I could give, and thanks to God we did well.

"The record is an additional bonus."

South Africa, the third fastest of the qualifiers, will line up in lane eight in Friday afternoon's final.

Semenya, meanwhile, cruised through the first round of the women's 800m, finishing second in her heat, although she was credited with the same time as Russian winner Mariya Savinova, clocking 2:01.01.

Semenya, the defending champion, did not want to speak to the media, but told a South African journalist in Sepedi that she was pleased with her performance ahead of Friday's semifinals.

"It was not a big deal, and I don't walk to talk," Semenya said.

"It went fine and I'm happy. It wasn't a big deal, I'm just doing one race at a time."

African record holder Sunette Viljoen qualified easily, heaving the best throw in her group by reaching 65.34m with her first effort to progress automatically in the opening round of the women's javelin throw.

Former continental record holder Justine Robbeson was eliminated, finishing 10th in her qualifying group with a best of 58.08m.

Khotso Mokoena, who picked up the silver medal in Berlin two years ago, was eliminated in the qualifying round of the men's long jump.

The pretender to his throne, however, sneaked through, with world junior champion Luvo Manyonga finishing fifth in his heat with a best of 8.04m.

Mokoena was ninth in the tougher of two groups, leaping 8.00m with his third attempt to miss qualification by only two centimetres.

Manyonga will compete in the final on Friday afternoon.

Robert Oosthuizen was eliminated in the qualifying round of the men's javelin throw, with a best heave of 73.14m to finish a lowly 16th in his group.

Elroy Gelant placed 10th in the heats of the men's 5 000m, clocking 13:48.33 and finishing almost eight seconds behind the slowest qualifier.