Swimming sensation Chad le Clos pushed South Africa six places up the medals table, to 10th position, as he bagged the country's second gold medal of the London Olympic Games on Tuesday evening.
Le Clos, 20, chased down American legend Michael Phelps in the last 50 metres, touching the wall in one minute, 52.96 seconds (1:52.96) to smash his own national record by well over a second in the men's 200 metres butterfly final.
Phelps, the defending champion, finished second in 1:53.01.
Le Clos's medal added to the gold won by Cameron van der Burgh in the men's 100m breaststroke final on Sunday.
The SA team were placed above the likes of Australia and hosts Great Britain in the table after the fourth day of competition.
An hour after the butterfly final, Le Clos was back in the water, swimming the third leg of the men's 4x200m freestyle relay final.
The SA quartet, consisting of Darian Townsend, Sebastien Rousseau, Le Clos and Jean Basson, got off to a superb start, with Townsend going out hard on the first leg.
They faded, however, with Rousseau dropping back on the second leg, and they were unable to close the gap, clocking seven minutes, 09.65 seconds (7:09.65) for seventh place.
The United States won in 6:59.70, with Phelps bagging his 15th Olympic gold medal.
Meanwhile, Gideon Louw narrowly missed out on a place in the men's 100m freestyle final, finishing fourth in the second semifinal in 48.44 seconds.
Louw, who set a personal best of 48.29 in the morning heats, was ninth fastest in the penultimate round, falling 0.06 seconds shy of a place in Wednesday's final.
Compatriot Graeme Moore failed to progress beyond the preliminary rounds, finishing seventh in his heat in 49.29.
Elsewhere, the SA men's lightweight fours rowing team of Matthew Brittain, Sizwe Ndlovu, John Smith and James Thompson qualified for Thursday's A final, finishing second of six boats in six minutes, 04.21 seconds (6:04:21) in the second semifinal.
Banyana Banyana produced their best performance of the Games, holding world champions Japan to a credible goalless draw in their last pool match of the women's football tournament.
Holding fort at the back for 90 minutes, the South Africans did well to keep out a relentless Japanese attack in their final appearance on Olympic debut.
The SA women's hockey side lost their second successive match of their campaign, going down 4-1 to world No 6 New Zealand.
Controversial equestrian Alex Peternell finished 49th of the 53 competitors who completed all three rounds of individual eventing.
Peternell won a case on the eve of the Games, at the Court of Arbitration for Sport (CAS), which forced the SA Sports Confederation and Olympic Committee (Sascoc) to include him ahead of Paul Hart, who was initially selected as the country's only horse rider.