Dustin Johnson, Justin Thomas and Bryson DeChambeau were among those to pack their bags as the field was cut to 16 at the WGC-Dell Technologies Match Play on Friday.
Top-seeded Johnson lost to Kevin Na, who finished birdie-birdie to turn the match and eliminate his fellow American from Group 1 on day three in Austin.
Scotland's Robert MacIntyre progressed out of the group after a tie with Adam Long, having landed one of the shots of the week with a spectacular drive on the 18th which ended up inside three feet and ultimately got him through.
"I had probably one of the best and one of the luckiest golf shots I've hit in my life," the Scot said.
"I had a bit of bad luck here and there and managed to turn it around right at the end there, and it's one of them things, you've just got to keep fighting until the end, and it just shows anything can happen in this game."
Johnson and Na's match was not without tension, with the 28th-seeded American tapping his opponent on the shoulder on the 11th green to warn him about collecting his ball before concession had been verbalised.
In a mildly tense exchange, Johnson appeared to apologise but walked away less than impressed.
DeChambeau, the fifth seed, bowed out at the hands of Tommy Fleetwood, who topped Group 5.
Fleetwood had established a 4up advantage through seven holes but stumbled, allowing DeChambeau back in the match. The Englishman finished with a par on the 18th to win.
"It turned really scrappy for a lot of the back nine," Fleetwood said. "He started coming back and on the last an unlikely par. Match Play is that funny all week. There are guys who have played better than me for three days who are going home and I'm going through."
World number two Justin Thomas was another casualty, despite defeating 2010 Open champion Louis Oosthuizen 3 and 2.
There were eight playoffs required, with Jon Rahm, Bubba Watson and Sergio Garcia among those winning to join the likes of Jordan Spieth in the last 16.
Garcia delivered an incredible shot to beat Lee Westwood, making a hole-in-one at the fourth hole.
Rory McIlroy was also eliminated, tying with Cameron Smith as Ian Poulter finished top of Group 11 after three wins.