Two-time major champion Dustin Johnson has resigned his membership of the PGA Tour in order to play in the Saudi-funded LIV Golf Invitational Series.
The former world number one will play all eight events of the fledgling $255m (£200m) series, which starts on Thursday at Centurion Club near London.
Johnson, 37, joined the PGA Tour in 2008 and has won $74m in his career.
"I don't want to play for the rest of my life, this gives me an opportunity to do what I want to do," he said.
Johnson's announcement was an explosive start to a week that threatens to blow apart elite men's golf.
Fellow American Kevin Na said earlier this week he was quitting the dominant PGA Tour to play in LIV Golf events, but Johnson's decision trumps that.
He spent 135 weeks as world number one, was the PGA Tour player of the year in 2016 and 2020 - the years of his respective US Open and Masters triumphs - and was also crowned FedEx Cup champion two years ago.
In quitting the PGA Tour, Johnson - who is reportedly receiving $150m in appearance fees to play in the Greg Norman-fronted LIV series - is giving up his opportunity to feature in future Ryder Cups.
He has been on the winning side in two of his five appearances in the biennial competition against Europe, including winning all five of his matches in last year's record 19-9 victory at Whistling Straits in Michigan.
"The Ryder Cup is unbelievable and has meant a lot to me, but ultimately I decided this was best for me and my family," he said.
"All things are subject to change and hopefully at some point it will change and I will get a chance to do that again."
PGA of America chief executive Seth Waugh said last year: "If someone wants to play on a Ryder Cup for the US, they're going to need to be a member of the PGA of America, and they get that membership through being a member of the (PGA) Tour."
Johnson's decision represents a significant u-turn given he said in February he was committed to the PGA Tour, which has threatened sanctions and potential bans against players signing up for LIV Golf.
When asked what had changed in such a short space of time, the world number 15 simply replied: "I thought it was best for me and my family. I resign my membership of the PGA Tour.
"What the consequences are going to be I can't comment on how the Tour's going to handle it. I can't answer for the majors but hopefully they're going to allow us to play.
"Obviously I'm exempt for the majors so I plan on playing there unless I hear otherwise."
The majors are not run by the PGA Tour and Johnson's victory two years ago in the Masters gives him a lifetime exemption for the tournament at Augusta National. His 2016 US Open triumph guaranteed him a spot in his national championship for 10 years. His Masters win also gives him a five-year exemption for The Open and US PGA Championship.
The Open and US Open, which starts on 16 June at Brookline in Massachusetts, would have to introduce a special clause to disinvite any players competing in LIV Golf events.
Six-time major champion Phil Mickelson will also play at Centurion in what will be his first appearance following a four-month break from the game.
The American, who has been given a reported $200m to feature in the start-up series, has not played since controversial comments about the Saudi-funded events were published by his biographer in February. He is expected to talk to the media on Wednesday.
It has also been reported Spain's Sergio Garcia and South Africans Louis Oosthuizen, Charl Schwartzel and Branden Grace, who are all in the 48-man field for the event on the outskirts of London this week, have all resigned their membership of the PGA Tour.
However, Northern Ireland's Graeme McDowell has not resigned, saying he did not want to get in a "legal situation" with the organisation.
His future participation in the Ryder Cup would be determined by the European-based DP World Tour.
McDowell last played in 2014, four years after holing the winning putt at Celtic Manor. He was a vice-captain in the victorious team in Paris in 2018 and again on the losing side last year.
The 42-year-old Northern Irishman, who won the US Open in 2010, has been touted as a potential captain of the European side when the Ryder Cup is played at Adare Manor in the Republic of Ireland in 2027.
"With regards to the Ryder Cup, it's something I weighed up long and hard before I made the decision to come out here. I hope it doesn't affect that," he said.
"When you look at the European Tour, the players here have done a great amount for the Ryder Cup product and it would be a shame to see those guys not invited back.
"Is it healthy for the sport? This Tour is designed to be an add-on to the greatest tours in the world."
Fellow European Ryder Cup players Lee Westwood, Ian Poulter and Garcia are all at Centurion this week.
'We are proud to help Saudis grow the game'
McDowell also fielded questions about the morality of playing in an event that has been funded by money from Saudi Arabia, given the nation's human rights record and accusations of sportswashing.
"The Khashoggi situation, we all agree that was reprehensible," he said, referring to the murder of Washington Post reporter Jamal Khashoggi inside the Saudi consulate in Istanbul in 2018. "No-one's going to argue that fact but we're golfers. We're not politicians.
"Golf is a force of good in the world and I love using the game as something to help grow around the world and be role models to kids.
"If Saudi Arabia want to use the game of golf as a way for them to get to where they want to be, we're proud to help them on that journey, using the game of golf and the abilities we have to help grow the sport."
Asked specifically how golf is helping repressed groups in Saudi Arabia, McDowell added: "I wish I had the ability to be able to have that conversation with you.
"As golfers if we tried to cure geopolitical situations in every country in the world that we played in, we wouldn't play a lot of golf. That's a really hard question to answer. We are just here to focus on the golf."
The $25m (£20m) purse on offer this week at Centurion Club near St Albans is the most lucrative ever played for on British soil, with $4m going to the winner of this first of eight events to be played in 2022.
This initial invitational series will feature six more regular season tournaments in 2022 - four in the United States, one in Thailand and one in Saudi Arabia - each having the same $25m prize fund, meaning every leg of the series is more lucrative than the richest tournament on the PGA Tour.
The events will feature a team and individual competition, with 12 captains selecting three players in a draft-style format. Each day, the teams of four will tee off at the same time on different holes in what is termed a 'shotgun start'.
Each event's individual winner will take home $4m - by way of comparison, the PGA Tour's flagship event, the Players Championship, earned Cameron Smith $3.6m for his victory in March, while Collin Morikawa won $2m for his Open Championship victory in 2021.
The eighth and final event, at Trump National Doral in Miami in October, will be a $50m 'Team Championship' matchplay knockout tournament featuring 12 teams. The winning team will receive $16m, with each of the four players earning a 25% cut.
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