The Spaniard had beaten fellow Ryder Cup veteran Lee Westwood 4&3 on day one and another excellent performance put him in control of an all-European Group Eight at Austin Country Club.
Westwood bounced back with a 5&3 victory over Matt Wallace to keep his chances alive but Garcia needs just a half against the same opponent on day three to advance to the last 16, with Wallace and Hatton eliminated.
Garcia has a base in Austin and admits he feels very much at home at this event, as he looks to make the last 16 for the third consecutive year.
"I love Austin, it's a really, really cool city. Probably in my opinion probably the best city in the country," he said.
"Both matches yesterday and today, they're two guys that obviously are friends of mine and they're really, really good players, so you know that it's going to be tough and you just hope that you go out there with your best game and get the W."
The 41-year-old birdied the second from 23 feet and a Hatton bogey on the fourth had him two up at the turn.
A tee shot on the 11th to 12 feet extended the advantage but better was to come at the 13th as he put a three wood to four feet on the par four. A birdie was enough to give him a four hole lead and Hatton winning the 15th only delayed the inevitable.
Westwood and Wallace were all square at the turn but Wallace bogeyed the tenth and the reigning Race to Dubai champion rattled off three birdies in a row from the 11th to take control.
Johnson birdies from three and 30 feet on the first and third sandwiched a MacIntyre gain on the second, and the Scot was back level on the ninth as he put an approach to eight feet.
A lengthy putt on the tenth put MacIntyre ahead and when Johnson found the water on the 11th, the 2019 Sir Henry Cotton Rookie of the Year led by two.
He still held that lead on the 16th tee but the 2017 champion showed why he is the top seed this week, hitting the green in two and making an eagle before putting his tee shot to 17 feet and rolling home on the next.
"I was dying to win that match," said MacIntyre. "I was in such a great position to do it.
"But he threw everything at me and I can be proud of finishing there all square but obviously inside I'm a little disappointed not to win.
"But once we walk away from here and get in the car and drive back to the house, it's going to be, 'You know what? I can compete with these best guys on the planet'."
Once we walk away from here and get in the car and drive back to the house, it's going to be, 'You know what? I can compete with these best guys on the planet' - Robert MacIntyre
Lowry moved two up after three holes but it was the 2019 Race to Dubai champion who led by one at the turn in a topsy turvy contest.
Rahm led by three with three to play but Lowry hit the 16th in two for a birdie and then put his tee shot to eight feet on the 17th before conceding the last to Rahm, who now faces Ryan Palmer in a winner takes all contest.
"I'm not going to expect many mistakes from him," Rahm said of Palmer. "He's an absolute ball striker and he's a Texas man, which means in the wind and gusts and this kind of golf course, he's comfortable. It's going to take everything I've got."
The Frenchman produced the result of the day on Wednesday as he defeated U.S. Open champion DeChambeau but after a nip and tuck start against Fleetwood, he bogeyed the eighth and ninth to find himself three down.
Fleetwood hit an excellent tee shot into the par three 11th and while Rozner hit back on the 13th, a bogey on the next left Fleetwood dormie four.
"Bryson's been smashing it literally and figuratively, he's been doing great and clearly great for the game and it will just be nice to go toe to toe with him and see what we can do," said the Englishman.
DeChambeau was a 2&1 winner against Si Woo Kim on day two.
The 2018 Masters Tournament winner holed from 20 feet on the first and 16 on the fifth and, while Bezuidenhout won the sixth, Reed birdied the eighth and parred the ninth to lead by three at the turn.
The duo shared two wins a piece from the tenth to the 13th and while Bezuidenhout trimmed the gap on the 16th, a pair of pars on the next handed Reed victory.
There will be a winner takes all repeat of the 2019 final in Group Two, as Kevin Kisner and Matt Kuchar go head to head with two wins out of two, as Louis Oosthuizen and World Number Two Justin Thomas contest a dead rubber.