South Africa's marathon runners failed to fire in the London Olympic marathon, with only two of the three athletes completing the Sunday's race.

Ugandan Stephen Kiprotich took the gold medal in 2:08:01, followed by the two Kenyans, Abel Kirui (2:08:27) and London marathon winner Wilson Kiprang Kiprotich (2:09:37) for silver and bronze, respectively.

On one of the hottest days of the London Olympics, Stephen Mokoka, April Lushapa and Coolboy Ngamole were punching above their bodyweight taking on the leaders, with Mokoka holding a top ten position in the early stages.

Predictably, a slight increase in pace early in the third lap saw the cracks appear and Mokoka lost 38 places in the last 12km to finish 49th in 2:19:52.

Lushapo April beat him to line by six places and 52 seconds.

"I was comfortable with them until 29km, but just couldn't hold on," said the 27-year-old Mokoka.

"The guys caught me at 34/35km and they were coming at pace. I couldn't stick with them.

"If I could run it again I would run it the same way as I was training for 2:06."

Mokoka will return to discuss the future with coach Michael Seme, who coached Caster Semenya to the Berlin 800m World Championships.

An exhausted Coolboy Ngamole withdrew from the race on the Embankment with less than seven kilometres remaining, having already dropped into the fifties.

From a conservative start, Zimbabwean Cuthbert Nyasango moved through from 29th at 10km to finish seventh in a personal best 2:12:08, with country man Wirimai Juwawo running a seasons best 214:09 in 15th position.