BEIJING (AP) — Kaillie Humphries crossed the finish line, jumped from her sled and hoisted an American flag that someone had just handed her into the frosty air.

"U-S-A! U-S-A!" she chanted.

Four years ago, nobody would have seen that coming. The former Canadian bobsled heroine is an Olympic gold medalist for the third time — and for the first time, as a U.S. citizen.

Humphries is monobob's first Olympic champion, finishing off a surprisingly easy win at the Beijing Games on Monday. She completed four runs in 4 minutes, 19.27 seconds to lead a gold-silver finish for the U.S. women's program, with teammate Elana Meyers Taylor placing second.

"As I age, I've learned life is very unpredictable and we don't always know our path forward and what the future holds," Humphries said. "We do the best we can with each and every obstacle or path change that gets thrown at us. What's important is to fight for ourselves."

Meyers Taylor was second in 4:20.81 — 1.54 seconds back — for her fourth Olympic medal, one that came after she took a year off following the Pyeongchang Games to become a mother. Christine de Bruin of Canada was third in 4:21.03.

Humphries gave the medal a big kiss as she put it around her neck, then put her hand over her heart and sang along with "The Star-Spangled Banner" as it blared in her honor.

Humphries became the first woman to win Olympic gold for two different countries, and the first Olympian to win gold for both the U.S. and Canada. She also is the first woman to win three golds in bobsledding, with a chance for a fourth later this week in the two-person event.

"I give so much credit to the coaches, the staff, the U.S. Olympic and Paralympic Committee for thinking about everything that can possibly go into supporting both Elana and Kaillie," USA Bobsled and Skeleton CEO Aron McGuire said. "And it worked out. Certainly, a storybook ending."

It was the biggest winning margin by far in any of the six Olympic bobsled races that have been contested by women, smashing the 0.85-second victory that Humphries enjoyed at the 2010 Vancouver Games.

And the last time any Olympic bobsled race saw such a margin between first and second place was 42 years ago, when Erich Schärer of Switzerland won the two-man event at the 1980 Lake Placid Olympics by 1.57 seconds.

"I'm one small piece of what this medal means," Humphries said. "It's taken a lot to get to this point."

Meyers Taylor is now a four-time medalist, giving her the most in USA Bobsled history — breaking a tie with three others, the great Steven Holcomb among them — and tying her for sixth most in U.S. Winter Olympic history.

Apolo Ohno (eight), Bonnie Blair (six), Bode Miller (six), Eric Heiden (five) and Chad Hedrick (five) are the only U.S. winter athletes with more medals. Meyers Taylor will vie for a fifth medal later this week in the traditional two-person women's bobsled event.

"It's bittersweet because I would have loved to see Holcomb win another one in 2018 and I know he would have, another two probably," Meyers Taylor said. "I think Holcomb's records are precious."

Like Humphries, Meyers Taylor also went through struggles to get here. Concussions nearly derailed her career, then she took a year off to have her first child, a boy born with Down syndrome and significant hearing loss. And in Beijing, she did a stint in isolation — spending more time away from her son than she ever had since his birth two years ago — after testing positive for COVID-19.

But it was fitting that Humphries and Meyers Taylor finished 1-2 — the first gold-silver finish for the U.S. in an Olympic bobsled race since 1932 — because  they were the ones who championed a second medal event being added to the women's bobsled Olympic program.

"I am to the moon with this medal," Meyers Taylor said. "I was, at one point, just trying to make it to the race. So to be here now, a silver medalist, it feels so amazing."

Humphries won three women's bobsled medals — two gold, one bronze — for Canada, then joined the U.S. team in 2019 after saying she had suffered mental and emotional trauma and no longer felt safe being a part of that program.

She made the switch knowing the Beijing Games were not guaranteed: A passport is required in almost all circumstances to compete at the Olympics, and Humphries was told it could be a four-year process. She had 2 1/2 years to get it done.

Humphries became a citizen in December after acing her final interview in San Diego, then flew back halfway across the world the next day to rejoin the World Cup circuit. More challenges awaited: A hamstring injury slowed her down at the end of the World Cup season, and then she tested positive for COVID-19 — a hurdle she didn't fully clear until earlier this month.

All good now. Good as gold.

"We've worked so hard for this and been through so much," said Travis Armbruster, Humphries' husband, as he watched from their San Diego home. "I couldn't breathe until she crossed the finish line."

Humphries controlled the whole race: up by 0.30 seconds after the first run Sunday, then 1.04 seconds at the midpoint and kept pulling away Monday.

De Bruin started the day second and ended up third. Laura Nolte of Germany started the day third and finished fourth, making this the first of seven sliding races so far at the Beijing Games that the Germans — who had won golds in the other six — didn't even medal. Meyers Taylor was the only medal contender who moved up Monday, going from fourth to second.

The only drama at the end was who would get the silver.

Gold had been won. Humphries made history. America had a new champion.

"I chose a nation," Humphries said. "And it chose me back. To know that we could do this together as a team, it's a huge honor."