Dustin Johnson says he has resigned from the PGA Tour in order to play in the new $255m (£204m) LIV Golf Invitational Series, which starts at Centurion Club near London this week.
The move also means that the former world No1 and two-time major winner will also be ineligible to add to his five appearances for the United States at the Ryder Cup.
The PGA Tour and its European counterpart, the DP World Tour, have threatened to ban players who participate in the new circuit, which is backed by Saudi Arabia’s Public Investment Fund.
But Johnson left the door open to a return to the PGA Tour, indicating that he hoped those threats would remain unenforced and he would be able to play further majors too.
“At this time it’s hard to speak on what the consequences will be but for right now I’ll resign my membership of the tour and I’m going to play here for now,” said the 37-year-old.
“What the consequences are going to be, I can’t comment on how the tours are going to handle [that]. Again, I can’t answer for the majors. 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.”
Johnson is the highest-ranked player in the field for the LIV Golf Invitational – London, which is due to begin on Thursday and offers the winner $4m (£3.2m) from a prize pot of $25m (£20m).
Six-time major winner Phil Mickelson, Sergio Garcia and Lee Westwood are also among the 48 players signed up for the Hertfordshire curtain-raiser to a series that promises to reinvent golf.
Tournaments will feature simultaneous individual and team scoring, three rounds instead of the usual four and shotgun starts, where all players tee off at once at different holes.
Most significantly, however, is that it is planned to evolve into a year-long league with 12 distinctive star-led franchises that LIV Golf chief Greg Norman hopes can emulate the success of cricket’s Indian Premier League.
Johnson said relinquishing his eligibility for future Ryder Cups had been a big decision but “hopefully all things are subject to change and at some point we’ll be able to participate”.
“It was another thing I had to really think long and hard about and ultimately I decided to come to this. Like I said, I’m excited about it,” he added.
“The Ryder Cup is unbelievable and has definitely meant a lot to me. I’m proud to say I represented my country. Hopefully I’ll get a chance to do that again, but I don’t make the rules.”
Asked whether he had chosen money over his country, he said: “I chose what’s best for me and my family.”
Johnson’s decision to resign, which follows a similar move from world top 40 player Kevin Na last week, promises to call the PGA Tour’s bluff.
The leading tours must now decide whether to issue bans and risk ostracising some of their biggest names or bow to player power, knowing other stars could follow suit.
Tiger Woods, Rory McIlroy and Jon Rahm are among the stars to have rejected advances from LIV Golf, which is backed by $2bn from the Saudi PIF.