Allyson Felix knows a thing or two about opening up a big lead on the competition.
She won her sixth Olympic gold medal on Saturday night, giving her two more than any other woman in track and field history.
Felix ran away from the field on the anchor leg to lead the United States to its sixth straight victory in the 4x400 meter relay Saturday night in Rio.
The win in an event the USA has dominated for decades came shortly after a surprise in one the U.S. hadn't won in more than a century — Matthew Centrowitz's surprise gold in the 1,500.
In Felix's race, Jamaica's Novlene Williams-Mills got up on her shoulder coming into the final stretch. But the most decorated woman in Olympic track and field history put her away, increasing the gap on the way to finish in three minutes, 19.06 seconds.
Jamaica was more than a second back for silver in 3:20.34 and Britain got bronze in 3:25.88.
American women have won this event six Olympics in a row. Since women first ran this in 1972, the only countries to win it have been the Soviet Union, East Germany and, in 1992, the Unified Team of former Soviet athletes.
Meanwhile, the U.S. had a medal drought longer than the very existence of the Soviet Union that came to an end in the men's 1,500 meters. Centrowitz won in 3:50.00 for the first U.S. title in the event since 1908.
Taoufik Makhloufi of Algeria won silver 0.11 seconds behind Centrowitz and Nicholas Willis of New Zealand was third.
"My goal was just to get on the podium, I didn't dream, ever dream, of winning,” said Centrowitz, who finished fourth in London in 2012.
Mo Farah won the 5,000 meters to take the distance double for the second Olympics, matching Lasse Viren of Finland.
American Paul Chelimo got a silver medal, after he was briefly disqualified, apparently for stepping on the inner boundary of the track, left exposed for field events. He was reinstated shortly afterward.
Hagos Girbhiwet of Ethiopia got bronze. He made a move on Farah with a lap to go, but couldn't outkick one of running's best finishers. US teammate Bernard Lagat was fifth.
Earlier in the Olympics, Farah won the 10,000-meter race, falling and getting up to win as Viren did in 1972.
The United States won the 4x400 men's relay, a day after the 4x100 relay team lost a bronze medal when it was disqualified after the race. Jamaica anchor Javon Francis ran a strong closing leg to lock up silver for his team, while the Bahamas got bronze.
Caster Semenya of South Africa won the women's 800 meters in 1:55.28 to add an Olympic gold medal to the silver she won in London. Burundi's Francine Niyonsaba was second and Kenya's Margarey Wambui was third.
American Kate Grace finished eighth.
In the high jump, the USA's Chaunte Lowe finished fourth. She had the same highest jump as the winners, at 1.97 meters, but her two failures before clearing it cost her the tiebreakers. Spain's Ruth Beita won gold, Bulgaria's Mirela Demireva got silver and Croatia's Blanka Vlasic earned bronze.
There were no Americans in the final of the men's javelin throw.
Felix's six career Olympic golds give her the most of any woman in track and field.