Carissa Moore of the U.S. and Italo Ferreira of Brazil win the first Olympic gold medals in surfing.

ICHINOMIYA, Japan — The fickle waves at the inaugural Olympic surf competition came roaring to shore on Tuesday, pushed by Tropical Storm Nepartak, leading contest organizers to try to jam the quarterfinals, semifinals and medal matches into one busy day.

Two by two, in head-to-head elimination rounds, many of the world’s best surfers paddled into the churning and unpredictable water, just days after they practiced in tiny, thigh-high waves.

One by one they emerged, either sent home or pushed onward toward the first-ever Olympic medals in their sport.

And through the foam rode Carissa Moore of the United States and Italo Ferreira of Brazil, two of the top surfers of the day, now the first to win Olympic gold medals in the sport.

Moore, 28, the four-time world champion born and raised in Hawaii, met underdog Bianca Buitendag of South Africa in the day’s last match at Tsurigasaki Surfing Beach, about 60 miles east of Tokyo.

Moore stamped her career with three victories in little more than six hours on Tuesday. The final buzzer brought tears to her eyes, and she blew a kiss to supporters on the beach in the fading daylight.

Buitendag, 27, had arrived through a string of upsets, beating seven-time world champion Stephanie Gilmore in the third round and 19-year-old American Caroline Marks in the semifinal. Although her ride ended without suspense against Moore, her consolation was a silver medal that few could have expected.

Ferreira, 27, the 2019 world champion and one of Brazil’s army of surfing superstars, beat Japan’s Kanoa Igarashi, 23, a Japanese-American born and raised in Southern California. He celebrated by standing in the knee-deep surf, throwing his arms to the sky, then wrapping his face in his hands. He was carried to the beach on the shoulders of two members of the Brazilian contingent.

Ferreira was swallowed by a wave after a big drop in the opening minute of the men’s final. The first thing that popped to the surface was half of his broken board. A fresh board was delivered to him on the beach, and Ferreira was soon riding to a pair of scores that gave him a lead he never relinquished.

“It’s one of the best days of my life,” Ferreira said. “For me, that was a long day. It was a dream come true.”

Igarashi, 23, had already knocked out one Brazilian superstar, Gabriel Medina, in the semifinal. Igarashi performed a 360-degree air with just seven minutes left in the 30-minute heat, earning 9.33, one of the highest-scoring waves of the Games.

“The ride was probably about seven seconds long, but it felt like 70 minutes long,” Igarashi said immediately afterward. “I felt every single little moment. I felt my heartbeat, I felt my hair in the wind, I felt being in the air. And I had thoughts while I was in the air. It was kind of surreal, but as soon as I landed it I knew it was one of the biggest moments of my career.”

It ensured him at least a silver medal.

In the men’s bronze-medal match, Medina was beaten by Owen Wright of Australia. Amuro Tsuzuki of Japan, who grew up riding waves on the surrounding coast, bested Marks to win bronze for the women.

The sudden decision to squeeze so much surfing into one day was made on Monday night, as the storm churned off the east coast of central Japan, sending swells toward Tsurigasaki Surfing Beach. Surfing’s unique schedule, or lack of one, originally had the contest ending no sooner than Wednesday, but it was determined that the wildest waves were coming a day early.

So two of the world’s best surfers, Igarashi and Kolohe Andino of the United States, set out in the rain and wind at 7 a.m. for a high-level quarterfinal. It was a bit like surfing in a washing machine, as the sloppy storm surf made for difficult conditions for the competitors and a bit of a spectacle for those watching. Igarashi advanced, spoiling Andino’s medal hopes.

If there was any apprehension about the uneven conditions, Medina pronounced the contest fully on in the next heat. He launched a skyward full rotation, landed smoothly and pounded his chest in celebration. Judges were impressed, too, giving the ride a 9.0, the highest score of the contest to that point.

But clean rides were sporadic. For most of the morning, the sea was more a roiling stew than a series of sets, better to look at than to surf.

“The waves go really fast, and then they just dump,” Moore said after a quarterfinal victory. “It’s kind of tricky to place your maneuvers in this kind of surf.”

When Marks won her quarterfinal, knowing there would be two more matches, she rushed out of the water to take the measure of the changing conditions.

Adapting was key; she had warmed up on one board, then competed on another. The tide was low but coming back, and the action was shifting north along the quarter-mile beach. There was a lot of paddling, and fatigue was a factor at the end of a long day.

“I’m having so much fun,” Marks said. “I’m here because I love surfing, and this is so rad.”

The Olympic field began with just 20 men and 20 women, and no more than two of each from any country. Most of the field was set before the pandemic, so five of the top 10 men and four of the top 10 women in the current World Surf League standings did not participate.

Most glaringly, that left out Filipe Toledo of Brazil, who has finished in the top four each of the past four seasons. And Kelly Slater, maybe the most famous surfer of all, could not secure one of the two U.S. spots.

Worries about the surf conditions for the Olympics began the moment that Tokyo was named the host and surfing was added to the docket. Japan’s Pacific coast has long stretches of beaches and good surf, but most compared it to the East Coast of the United States, not the turquoise big-barrel spots in places like Hawaii or Australia. It is more Jersey Shore than North Shore.

There was even talk of holding it in a wave pool, which would have built certainty into the schedule — and into the waves. But organizers were adamant that surfing is more than just riding. It requires studying the ocean, adapting to the ever-changing conditions.

When Olympic surfers got their first look at Tsurigasaki Beach last week, they were met with thigh-high breakers just a few strokes from the beach. It was easy to be skeptical.

But the storm was coming, and it landed hard.

Talya Minsberg contributed reporting.