LONDON - Swimmers Cameron van der Burgh and Chad le Clos shone for South Africa on the opening day of the London Olympic Games on Saturday.

Van der Burgh smashed the South African, African and Olympic records in the semifinals of the 100m breaststroke, touching the wall first in a time of 58,83 seconds.

The country's greatest prospect for a medal in the swimming pool, Van der Burgh said the record had boosted his confidence ahead of Sunday night's final.

"It was just pure delight to see the time . to see 58 on the board was great," he said.

Earlier, rising star Le Clos finished fifth in the men's 400m individual medley final in 4:12.42.

"I guess I wanted to win a medal after making the final but I can't complain," said Le Clos, competing in his maiden Games. "Last year I was, like, 24th in this event. Now I am fifth in the world, which is not too bad."

Le Clos, the second-fastest qualifier in the morning session, had won his heat, defeating Lochte in 4:12:24.

Riaan Schoeman finished sixth in the same heat, swimming in the lane next to Le Clos, but his time of 4:17.22 ended his Olympic campaign.

Elsewhere in the pool in the morning, Heerden Herman came seventh in his 400m freestyle heat, clocking 3:57.28, and he will now turn his focus to the 1500m freestyle heats next week.

Kathryn Meaklim finished sixth in her 400m individual medley heat, failing to qualify for the final. Her next event is the 200m individual medley on Monday.

Meanwhile, the men's lightweight four rowing team of Matthew Brittain, Sizwe Ndlovu, John Smith and James Thompson came second in their heat and qualified for Sunday's semifinals.

Fellow South African rowers Naydene Smith and Lee-Ann Persse were fourth out of five boats in the second heat of the women's pairs.

Their time of 7:14.31 earned them ninth place overall, which saw them qualify for the repechage on Monday.

Boxer Ayabonga Sonjica was eliminated in the opening round of the men's 56km bantam division, going down 15-6 over three rounds against Bulgarian Detelin Dalakliev.

Controversial equestrian Alex Peternell placed 36th, and second-last in his group, in the dressage section of the individual eventing competition.

Peternell, who was a late inclusion in place of Paul Hart after he won a case at the Court of Arbitration for Sport this week, will hope to improve his placing in the cross-country discipline on Monday.

The men's badminton pair of Dorian James and Willem Viljoen lost their opening group stage match 6-21, 12-21 against Mathias Boe and Carsten Mogensen of Denmark.

Michelle Edwards and Anneri Viljoen lost 8-21, 7-21 against Jung Eun Ha and Min Jung Kim of the Republic of Korea in their first match of the women's doubles competition.

The country's only entrants in beach volleyball, the men's pairing of Freedom Chiya and Grant Goldschmidt, also struggled on the first day of the Games.

Chiya and Goldschmidt went down 2-0 to the American duo of Jacob Gibb and Sean Rosenthal in their opening match of the preliminary round.