Uganda's Stephen Kiprotich won the Olympic men's marathon, beating Kenya's Abel Kirui and Wilson Kipsang.
Kiprotich led at the 37km mark, despite appearing to suffer discomfort in his leg minutes earlier, and went on to win Uganda's first medal at London 2012.
His time of two hours, eight minutes and 11 seconds was 26 seconds clear of Kirui in second, with Kipsang a further 70 seconds back.
Britain's Lee Merrien finished 30th and team-mate Scott Overall was 61st.
Kipsang had taken up the running after Brazil's Franck de Almeida's early break and led at the halfway stage.
Kiprotich and Kirui caught him up to leave a three-way fight for the gold medal.
The Ugandan looked to be struggling with an injury to the back of his leg, but unexpectedly surged to the front and pulled away.
"It means a lot [to Uganda]," said Kiprotich. "Since 1972 we have never won a gold medal, so they are very happy."
Uganda's last Olympic champion was 400m hurdler John Akii-Bua, who won gold at Munich in 1972.