The World Number One dispatched Sebastian Munoz 4 & 2 on Wednesday and was a 5 & 4 victor over Cameron Young in his second match.
That means the Spaniard needs just half a point against the already-eliminated Patrick Reed to make the knockout stages for the third time in his fifth appearance at this event as he chases a first World Golf Championships title.
"I'm happy, feeling good," he said. "Played good in both matches and today was a tricky day.
"Cameron started really good, three birdies through the first five and the wind was pumping.
"I kept playing solid. I kept playing good golf. I stayed bogey-free and he made a couple of mistakes and I think the momentum shifted and I was able to get the win."
The world No. 1 brought his “A” game to ACC. pic.twitter.com/ifrJWdtWYT— WGC-Dell Technologies Match Play (@DellMatchPlay) March 24, 2022
It was not all plain sailing for Rahm as Young birdied the first, fourth and fifth to go 2 Up after five but Rahm birdied the sixth and Young made a hat-trick of bogeys to put the 2017 finalist 2 Up at the turn.
Rahm then birdied the 11th and 12th before a bogey on the 13th left Young needing to win every hole for a half.
Reed and Munoz are both eliminated after their match finished All Square.
Richard Bland has his fate in his own hands in Group Nine after a nervy 1 Up win over Talor Gooch.
The 49-year-old is making his debut at this event this week after famously claiming his first DP World Tour win last season at the 478th attempt.
He now knows a victory over fellow Englishman Lee Westwood will see his week continue as he chases a place in the top 50 of the Official World Golf Ranking and another debut at the Masters Tournament.
"There's a lot to play for, certainly for me," he said. "I've just got to try and take care of Lee. But there's no easy game, doesn't matter, Lee's still a class act, always has been, always will be. It should be good fun."
A par on the third and a birdie on the next put Bland 2 Up before he won the seventh and eighth in the same fashion.
Gooch won the ninth with a birdie and the comeback was on as he made a gain on the 11th and got back level with a birdie on the 14th and par on the next.
Bland then put his tee-shot to 13 feet for a birdie at the 17th and the last was halved in pars.
Westwood claimed a vital win of his own as a 1 Up victory saw World Number 13 Bryson DeChambeau head home.
DeChambeau birdied the third but Westwood hit back on the next and won the seventh with a par to lead at the turn.
He was 2 Up after a gain on the 12th but it was DeChambeau's turn to hit back and bogeys from Westwood on the 14th and 15th meant the match was turned on its head.
An incredible second to eight feet on the 16th set up a Westwood eagle and a par was enough to hand him the last.
"It was great," said Westwood. "Just about had a bit of everything. Couple of wides from both of us, a lot of good shots, some nice putts, some good saves, so it was just kind of just the way you want match play matches to go.
"Came down to the wire at the end, I had to finish eagle-birdie and then a good par at the last to that tricky pin. So it was a good game, very up-and-down and it was tight."
The Irishman was 4 Up with four to play after winning the fourth and seventh with pars and birdieing the 12th and 14th but Van Rooyen went par-eagle-birdie from the 15th to take it up the last.
"Four up with four to play, it's so hard to win a match at this level against world-class golfers," said Lowry.
"I thought I had the match sewn up with four to go and it's amazing this game, this tournament, it's hard to win games. Especially these last four or five holes, anything can happen. I got dragged down the 18th and thankfully I managed to scrape a win."
In the other match in Group 16, Brooks Koepka claimed his second win of the week as he beat Harold Varner III 2 & 1.
In Group Eight, Dustin Johnson beat Matthew Wolff 4 & 2 and Mackenzie Hughes defeated Max Homa 2 Up.