Rahm narrows Koepka's lead as Masters moves into wet third round
Rahm, one of the 39 players who had to complete their delayed second rounds on Saturday, had been within a shot of Koepka before bogeying the final hole.
Five-times Masters winner Tiger Woods managed to battle through the wet and windy conditions to make the cut at three-over par 147 after shooting a one-over 73, but Rory McIlroy was among the big names to miss out on the final two rounds.
The second round was completed and the cut was made, the third round got underway at 11.30am (4.30pm BST) with threesomes off split tees in a bid to complete the round before sunset.
Spaniard Rahm had an eventful session back on course, making birdies on the par-3 12th and par-5 15th before, in driving rain, he bogeyed by three-putting the par-3 16th.
The world number three quickly made amends on the par-4 17th, where he rolled in a six-foot putt from the fringe for birdie.
Three-putting the final hole, however, left Rahm on 10-under 134 overall after shooting rounds of 65 and 69 as he targets a second major win to follow his 2021 triumph at the US Open.
"But I would have taken even par in the last four holes either way, and going through this afternoon, hopefully we play and I go with a lot of confidence," Rahm said.
Conditions could be challenging on the rain-soaked course.
"We don't know what kind of conditions we're going to have. The weather's supposed to get worse," said Rahm.
"The greens have somehow maintained somewhat firm... but we don't know what's going to happen. Just a couple of greens that already had some water on them, and we'll see but obviously if I play a little bit longer, might not be able to be as aggressive in some spots."
Friday's play had been cut short after stormy weather descended on Augusta National, with three of the course's trademark tall pine trees blowing over.
Organizers said that no spectators had been injured by the falling trees and while there was wind and the rain continued to fall on Saturday, there was no sign of thunder or lightning, which would halt play.
Temperatures have dropped sharply in the area, falling from 87 degrees F (30.5 C) in the bright sunshine of the opening round to 50 (10) on Saturday.
Four-time major winner Koepka, who plays on the breakaway LIV Golf series, is the man to catch after an outstanding opening two rounds.
At 118th in the world, Koepka would be the lowest-ranked player to win the Masters since the rankings system was introduced in 1986.
The current holder of that distinction is Angel Cabrera of Argentina, who was ranked 69th when he won the green jacket in 2009.
Tiger makes the cut
Woods, looking glum as he limped through the rain trying to avoid missing the cut for the first time as a professional, needed some help to get over the cut line.
The 15-time major winner looked to have blown his chance when he made a bogey on each of the last two holes to fall back to three-over.
But his friend Justin Thomas, last year's PGA Championship winner, then bogeyed the final two holes himself to move the cut line to three-over, saving Woods and ensuring he made the cut for a 23rd consecutive effort, matching the Masters record also shared by Gary Player and Fred Couples.
McIlroy shot a five-over-par 77 with seven bogeys on Friday, leaving him 17 strokes behind pace-setter Koepka and condemned to his second missed Masters cut in three years.
Sandy Lyle, the first British player to win the Masters in 1988, had been forced to leave the course on Friday whilst on the 18th green in his last Masters.
The Scotsman returned to putt out his round in 83 after his opening round 81 and received an emotional farewell from spectators who had flocked to the green.
