Jamaica's Elaine Thompson completed a memorable sprint double on Wednesday after storming to victory in the women's 200m final, blowing away the field with a season's best run of 21.78sec.
The 24-year-old 100m champion in Rio beat pre-race favourite Dafne Schippers of the Netherlands, who ran her fastest time of the season in the final but had to settle for silver.
Schippers, the world 200m champion, picked up a leg muscle injury ahead of the 100m final last week and said she almost pulled out of the Games.
After winning the 100m final, Thompson said she was surprised by her victory but she appeared in complete control after a brilliant start that helped her surge ahead of the field after the bend.
American Tori Bowie, who won a silver medal in the 100m final, grabbed bronze.
Ahead of the final, Bowie was the only woman other than Schippers to have run a sub-22 second race over 200m this year.
US clean sweep in hurdles
Brianna Rollins of the US won the 100m hurdles gold in a time of 12.48sec on Wednesday, leading compatriots Nia Ali and Kristi Castlin in the event's first ever Olympic podium sweep.
Ali was clearly in second place when she crossed the line to take silver in 12.59, but Castlin faced a nervous wait before it was confirmed that she had taken bronze in 12.61.
Britain's Cindy Ofili, also born in the US, pushed Castlin right to the line but lost out on a medal by two hundredths of a second in 12.63.
The US sweep was all the more remarkable given world record holder Kendra Harrison and 2008 Olympic champion Dawn Harper missed the Games after failing to make the cut at the US trials.
