Rory McIlroy is in contention for the top 10 heading into the final day at The CJ Cup after completing his third round.
The world number four was 12 shots off the pace after opening with rounds of 73-69, but fired a superb six-under 66 on Saturday to move to eight-under for the tournament.
He went into Sunday seven shots behind Russell Henley, who on 15-under led by three strokes ahead of a quartet of fellow Americans including second-round leader Xander Schauffele.
Shane Lowry is eight shots further back on level par after a 70 which also represents his strongest round at the Shadow Creek Golf Course in Las Vegas.
The Offaly man carded three birdies, with just a single bogey on the 13th.
Tyrrell Hatton was three shots off the lead in second place on Friday night but followed rounds of 65-68 with a one-over 73.
The 29-year-old Hatton endured a consistent but frustrating day, with eight pars on the front nine against one bogey, before cancelling out a bogey five at the 14th with a birdie four on the last after hitting his second shot to within eight feet.
McIlroy powered home to rise within reach of the lead. The Down golfer took birdies on the par-four third and sixth holes, dropped a shot on the long seventh, but then made six birdies against just one bogey in playing his back nine in five-under, including birdying his last three holes.
Henley was an unspectacular model of consistency in building his lead, with two front nine birdied and three more to kick off his back nine, in his bogey-free round.
"I putted really well. Left myself in some good spots to make some birdies and had some really nice par saves and scrambled well. Did a lot of good things," said Henley, who has had just two bogeys through three rounds.
The 31-year-old, who finished tied at 27 in last week's Shriners Hospitals for Children Open, had three consecutive birdies on the back nine and said he hoped to keep the momentum up in the final round.
"You can go low out here, the greens are great and it's gettable, but you've got to play well to do that. You've got to do everything well," he added. "I've got to just keep my head down and play a good round for me."