Finau’s Masters misadventure took place during the par-3 contest. After acing the seventh hole, he took off running in celebration, spun around, stumbled, landed awkwardly and popped his left ankle out of place. As his wife looked on, flabbergasted, Finau pushed the boneback in place as if he were clicking together Lego pieces. He then walked Augusta National’s hilly terrain for four days on the bruised, swollen joint, and finished in a tie for 10th.

No one would be shocked if Finau, 28, improved on that showing at this week’s United States Open. The Shinnecock Hills course, with five of its par-4s measuring at least 485 yards and a 616-yard par-5, favors his length off the tee; he is ranked second on the tour in driving distance (315.3). He also has become a fixture on the leader boards, with 11 top-25 finishes in 18 starts this season.

“He’s become a complete player,” said Phil Mickelson, the five-time major winner who is seeking his first United States Open title. “He obviously has power, but what he’s really developed is his ability to hit shots into targets, to work his short irons, to maneuver the ball.”

Less than two months after spraining his ankle, Finau was maneuvering on a trampoline in the backyard of his home in a Salt Lake City suburb. Playing bouncy games probably wasn’t what the trainers for the N.B.A.’s Utah Jazz, who treated Finau after he returned home from the Masters, would have ordered. But that’s what his four children requested, and in Finau’s world, family rules.

No, he is definitely not your typical PGA Tour member, and not just because his first sport was fire-knife dancing, a Samoan ritual. Or because he learned to play golf by swinging at targets on mattresses hung from the ceiling of his family’s garage.

Finau dislocated his left ankle during the par-3 competition the day before the Masters, then popped it back into place and played the whole tournament, finishing in a tie for 10th. Charlie Riedel/Associated Press

Finau is the tour’s first full-time player of Samoan and Tongan descent. He is also the third oldest of seven siblings and one-half of the closest equivalent in men’s golf to tennis’s Serena and Venus Williams. Like the Williamses, Finau and his younger brother Gipper, who plays on the minor-league circuit, were taught by their father. Gary Finau, who was a Delta Air Lines baggage handler, had never been exposed to the sport before his boys gravitated to it.

“I used to think, ‘Who in their right mind would go hit a golf ball?’” said Gary, who quickly embraced the sport as a father-son bonding exercise.

Gipper, who is 11 months younger than Tony, tried to qualify to join his brother at Shinnecock, but did not make it past the final stage. Gipper took up golf first, and was routinely beating players three or four years older when Tiger Woods won the 1997 Masters, a performance beamed into the family’s living room.

The Finaus couldn’t afford cable television, but they didn’t need it to behold that 12-stroke victory and the first time a man of color slipped on the champion’s green jacket. Tony, who was 7, saw his future that day.

“Here was a guy playing golf who had the same skin color as me,” he said. “As a kid, I could relate to that.”

Gary Finau said that the game came easier to Gipper but that no one worked harder than Tony. Those humble beginnings are a speck in his rearview mirror, but Tony remains far from satisfied. On a white board in his home office, he keeps a list of his goals, updating them frequently. They include winning a major by the end of 2019. Finau, who has one tour win in his career and is ranked 37th in the world, said he was aiming to ascend to the world No. 1 spot by his 32nd birthday.

There are other goals on his list, but they are hard to decipher because the board doubles as a canvas for his children, who have drawn squiggly lines and amorphous figures over his writing.

Finau’s list of goals shares space with doodles by his children.Alex Goodlett for The New York TimesFinau displays his trophy from the 2016 Puerto Rican Open, the one PGA Tour event he has won, and the cover of a magazine that published an article under his byline.Alex Goodlett for The New York Times

When Tony and Gipper Finau were young, most of their Polynesian friends embraced team sports like football, rugby, volleyball or basketball. That preference, according to John Mayer, an associate professor of the Samoan language at the University of Hawaii at Manoa, is rooted in the collective culture of Pacific Islanders.

“They tend to like to be part of a wheel rather than an individual spoke,” Mayer said.

The Finaus turned golf into a team sport. It was them against the world, two kids with secondhand clubs and generic clothing taking on the country club set. To help them, Gary relied on an illustrated book by Jack Nicklaus and instructional videos from the library. Once a week the boys splurged on a $7.50 bucket of balls at the local practice range. The rest of the time, to save money, they practiced in their garage, hitting off scraps of carpet into mattresses with targets drawn on them.

“I wouldn’t be as good as I am if I didn’t have a brother who pushed me at such a young age,” Tony said.

When he was about to turn 14, Finau planned to enter a public high school, Salt Lake’s East High,where he could expect to prosper athletically but would be separated from his older siblings. They attended Salt Lake’s West High, which had no golf team at the time. His mother, Ravena, objected to placing athletics above family and challenged Tony to put golf in its proper place. If West High was good enough for his older siblings, she said, it was good enough for him.

“She basically put her foot down and said that if you’re as good in golf as you think you are, you’ll figure it out,” Finau said. “It was a life lesson I’ve never forgotten. She basically was saying that what I needed to succeed, I already had. It was inside me.”

He enrolled at West, and then recruited classmates to join the golf team. It was a challenge filling out the roster. But by Finau’s junior year, he had assembled a special group. Gipper had arrived, and so had a girl, Daley Owens, who would earn a golf scholarship to Rutgers. With the driver’s education teacher serving as the coach, West won Utah’s 4A state championship.

“It was like a miracle, really,” Finau said.

Finau at the Junior Ryder Cup when he was 16. He turned pro at 17, before he finished high school.Richard Heathcote/Getty Images

Your typical PGA Tour player does not turn pro ahead of his high school graduation, but Finau did, at 17, in tandem with his brother. Seventeen family members showed up for the official announcement.

In their first event, Tony and Gipper competed for a $2 million first prize at the Ultimate Game in Las Vegas, with Tony advancing to the final 12. He earned enough to pay back his sponsors, who had covered his $50,000 entry fee, and had about $50,000 left to seed his career.

He needed every last dime; between 2007 and 2014, Finau cashed one PGA Tour paycheck, for $7,960. Though his career was progressing slowly, his personal life moved forward quickly after a New Year’s Eve dance in 2010, when he met Alayna Galeai, a volleyball player for California’s Notre Dame de Namur University.

Alayna, who was in Utah visiting relatives, was taken aback when she found out what Finau did for a living. “I was like, Polynesians play golf?” she said.

A week later, Alayna, her father and some of her friends went to the Sony Open in Honolulu, not far from where she grew up. They watched Finau make what turned out to be his only PGA Tour start of 2011.

“I remember he teed off on one of the holes and the crowd was ‘wowing’ in amazement,” Alayna said, “and I turned to my dad and asked what happened. And he told me, ‘Tony hits the ball far.’”

Finau and his family, including his wife, Alayna, far right, making lunch at home in Utah last month.Alex Goodlett for The New York Times

Finau soon told Alayna he aspired to be married with eight to 12 children. She wasn’t scared off. In November 2011 the couple welcomed their first child, a son named Jraice. They married in May 2012, five months before the birth of their daughter, Leilene. (They have since welcomed two more sons, Tony Jr., who is 3, and Sage, 2.)

Finau’s mother never got to hold his children. The day before Jraice entered the world, Ravena Finau was killed in a car crash. She was 47. Between her death and the dawning of his new life as a father and husband, Tony felt overwhelmed. At 22, he had a bleeding ulcer.

“I look back now, it was extremely tough,” he said.

Tony and Alayna lived with his father for a while and then, with their first two children, ended up in a one-bedroom apartment. It was furnished with thrift-store finds, and the couple often struggled to cover the $650 rent.

But the experience brought them closer, Tony said, and he found more success in golf as he took on more responsibility at home.

“Having a family, taking care of your kids and people outside yourself, maybe it’s motivated me more to give that extra something,” said Finau, who has as many children as his boyhood friend Rory McIlroy has major trophies.

“It’s admirable,” said McIlroy, who spent a summer in Utah as a junior player. “I think at 29, I’m just about getting my head around having kids.”

Finau in a practice round this week at Shinnecock Hills, which is hosting the U.S. Open. Nicole Bengiveno for The New York Times

Today the Finaus live in their dream house, four miles up the hill from that first apartment yet a world away, with its indoor basketball court, home theater and sweeping valley views.

Last month Finau skipped one of his favorite tour stops, in Dallas, so he could attend Jraice’s flag football championship. Finau joined four dozen relatives on the sidelines to cheer on his firstborn. Four days later, he attended Leilene’s Polynesian dance recital before returning to the road to tune up for the United States Open, which begins Thursday.

“Priceless moments,” Finau said.

A victory on Sunday — Father’s Day — would be meaningful, for sure. But then, every day is Father’s Day for Finau.

“I have these special goals,” he said, “but I can never forget what brings me the most joy and the most happiness.”

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Karen Crouse is a sports reporter who joined the Times in 2005. She started her newspaper career at the Savannah News-Press as the first woman in the sports department. Her first book, “Norwich,” was published in January, 2018. @bykaren