Kenya's Beatrice Chebet produced a masterful display of tactical running to win gold in the Olympic women's 5,000m on Monday, ending defending champion Sifan Hassan's dream of a long-distance treble.
Chebet -- nicknamed "the smiling assassin" -- bided her time before accelerating past compatriot Faith Kipyegon down the home straight to take gold in 14min 28.56sec at the Stade de France.
Kipyegon, the reigning 5,000m world champion, was initially disqualified from the silver medal position for an alleged shove on Ethiopia's Gudaf Tsegay with two laps to go.
However, she was later reinstated after an appeal from Kenyan officials.
Following that appeal, Dutchwoman Hassan was bumped back down from silver into bronze after finishing in a time of 14:30.61.
Hassan, 31, had been aiming to become the first woman in history to win 5,000m, 10,000m and marathon gold at the same Olympics, emulating the feat achieved by men's distance-running great Emile Zatopek at the 1952 Helsinki Games.
But after deploying her favoured tactic of staying at the back of the field for most of the race, Hassan was unable to live with the pace of Kenya's Chebet and Kipyegon in the final stages of a thrilling race.
Kipyegon edged just clear of Chebet coming down the home straight but was unable to respond when her compatriot found an extra gear and swept past her.
"I knew Faith is very strong so I had to go hard from 400 metres out," Chebet said afterwards. "When she pushed, I thought, 'Let me follow her and see if I can secure second.' If I followed Faith, I thought I would get the silver.
"Then at 400 metres to go I felt strong, so I pushed, then kicked again at 300 metres. Luckily I was able to win."
Chebet's victory was the latest milestone in a dazzling season for the 24-year-old Kenyan, who set a world record in the 10,000m in Eugene, Oregon in May.
Chebet will now look to seize Hassan's Olympic 10,000m crown when the race takes place on Friday.