A changing of the guard in women's sprints doesn't mean a redrawing of the map.

The 100m Olympic gold medal is heading back to Jamaica, only this time in the hands of Elaine Thompson, the 24-year-old who took down the USA's best, to say nothing of her training partner, two-time defending champion Shelly-Ann Fraser-Pryce.

Thompson turned what was supposed to be one of the most competitive races on the Olympic program into a runaway on Saturday.

Running even at the halfway mark with Fraser-Pryce and Tori Bowie of the United States, Thompson pulled away over the last half and defeated Bowie with a sizeable slice of daylight in between.

Thompson finished in 10.71 seconds, a full .12 better than Bowie and only .01 off the time she ran to beat Fraser-Pryce at Jamaica's national championships last month.

Thompson's 10.70 in Kingston was the best of five sub-10.8 women's sprints this year and served notice that things could be changing once the sprinters reached Rio.

"Jamaica has so many talented sprinters," Thompson said. "To be the second champion, I'm really happy."

Three of those sub-10.8 women were in the final - Bowie and another American, English Gardner, were the others - as was Fraser-Pryce, the 29-year-old who was a newcomer when she won her first of two golds at the Bird's Nest in Beijing eight years ago.

The evening's best drama came earlier in the men's 10,000 meters, where Britain's Mo Farah defended his title, rallying after he tripped and fell with 15 laps to go.

Day 2 closed with Jessica Ennis-Hill coming up 35 points short of defending her title in the heptathlon.

In between, US long jumper Jeff Henderson leapt 8.38 meters to overtake Luvo Manyonga of South Africa to claim gold on his last jump.

Fraser-Pryce was trying to become the first person to win three straight 100m titles at the Olympics. It would've given her one day's worth of bragging rights over Usain Bolt, who has overshadowed her in almost everything despite their dual dominance. Bolt will try to do it in the men's final on Sunday.

Fraser-Pryce led early, but faded and had to settle for a bronze medal - won by only .007 over surprise finalist Marie-Josee Ta Lou of Cote d'Ivoire - to go with the green-and-yellow hairdo she worked up for her turn as Jamaica's flagbearer in the opening ceremony.

She had been struggling with a toe injury that she said made even getting to the line an accomplishment.

"By far, I would say this is my best championship ever," Fraser-Pryce said. "I knew how hard I worked, I knew the pain, I knew the sacrifice, I knew the tears, I knew everything."

And now, there's a new champion from the island country that seems to grow them on trees.

Thompson was a late bloomer. Until she finished second in the 200m at last year's world championships, she barely made a splash on the international scene, tucked behind Fraser-Pryce and the country's seven-time Olympic medalist, Veronica Campbell-Brown, among others.

Thompson's win over Fraser-Pryce at the nationals caused a stir, but then both runners took to the sideline - Fraser-Pryce with the toe injury and Thompson with a strained hamstring.

She looked no worse for wear over three heats in Rio. In the final, she got stronger as she approached the line and left the field far behind.

Mo makes history after tumble

Distance runner Mo Farah said he was thrilled to make history after becoming the first British athlete to win three Olympic track gold medals after defending his 10,000m title on Saturday.

Farah tumbled to the track after he was clipped by US training partner Galen Rupp on lap 10 of the 25-lap race, but he quickly got up and continued running.

"When I fell, I thought the dream was over - I dug deep," said Farah, who has now racked up eight straight wins in the 5,000 or 10,000m at a world championships or Olympics since 2011.

"I promised my eldest daughter Rihanna a medal, so I couldn't let her down. That's why I was so emotional at the end."

Farah was guided back into his rhythm by Rupp, biding his time until the final two laps.

While Kenyan Paul Tanui made a break after the bell signaling the last lap, Farah kept him in sight and a surged through for a historic defense of his title.

Ethiopia's Tamirat Tola claimed bronze.

Should Farah also successfully defend his 5,000m title, he would become the first athlete since Finland's Lasse Viren in 1976 to retain two Olympic distance titles.

"Over the last four years, I'm sure people have been watching me win the worlds, so I've got a target on my back," said Farah, who was born in war-torn Somalia before moving to neighboring Djibouti and then Britain at the age of 8.

"It feels amazing, incredible to win medals for my country.

"This is what I've been training for. It's nice to be able to make history and make my nation proud.

"For the 5,000 meters, I just have to recover now, get through the heat and see what happens.

"I'm more of a guy who wins medals rather than runs fast times. One of the things that keeps me going is winning medals."