LIV Golf standard bearer Koepka and Rahm teed off under bright skies after two days of rain-interrupted play that forced golfers back early to complete their third rounds.
With the crowds shedding rain gear and putting umbrellas away, Koepka drew gasps from the gallery when his opening tee shot sailed all the way onto the adjacent ninth fairway.
But the four-time major winner followed up with a brilliant blind second shot over the pine trees that found the green allowing him to save par.
What had appeared to be a two-horse race turned into a three-way battle as Norway’s Viktor Hovland staged a back-nine charge to get within three of the leader and stayed in the thick of the hunt with a par at the first.
When play was halted on Saturday, Koepka was four ahead of Rahm and seven clear of the next nearest threat leaving the field needing to produce something special to challenge the frontrunners.
Hovland did just that – trailing by 10 at the turn, the 25-year-old ran together five consecutive birdies from the 11th for a two-under 70.
Cameron Young was making a final round charge collecting three birdies on his opening five holes to get to five-under but still with a lot of work ahead sitting six back of the pacesetter Koepka.
Critics of LIV Golf have branded the Saudi-bankrolled big-money venture as uncompetitive and little more than a sportwashing enterprise by a country eager to polish its human rights record.
A Koepka victory will not end the human rights questions but would give the breakaway circuit some of the credibility and legitimacy it craves.
If Koepka were to walk away wearing the Green Jacket it would be a major marketing coup for the rebel circuit which also has reigning British Open champion Cameron Smith of Australia among its members.
The final day at Augusta was played without golf’s biggest name after Tiger Wood’s withdrawal 75 minutes before third-round play resumed at 8:30am.
Woods, the last of 54 players to make the cut, was limping down the 17th fairway on six over par through seven holes when play was called off on Saturday due to bad weather.
The 47-year-old American has won the Masters five times, most recently in 2019, but he has struggled since his car crash in 2021.