Kevin Na produced an outstanding finish to Maintain a share of the Guide since Brooks Koepka crashed out of the Shriners Hospitals.
Na holed over 125 feet of putts over the previous six holes, just two of them falling for eagle in front of a birdie-birdie finish capped a great 62 on the following day of scoring at TPC Summerlin, while 2017 winner Patrick Cantlay fired a 64 to combine the four-way tie at the top.
Brian Stuard (65) and 2009 US Open champion Lucas Glover (63) also go into the weekend 12 under par, but Koepkas first start since losing out to Rory McIlroy in the Tour Championship in August resulted in a missed cut by four shots.
Na cruised to the turn in 31 prior to dropping his only shot at the day in the 10th, but he enjoyed an unbelievable run of form on the greens down the stretch, holing putts from 45 feet at the 13th and 35 ft in the 15th – equally for eagle.
The 36-year-old got additional chances to drop from external 20 feet on each of the two greens to complete the score of the next day in.
Yeah, my putter had been hot, said Na having a wry smile afterwards. I began using a 60-footer about the first pit, and I just kept making alterations now. I hit a lot of photographs, too, but the putter was working.
It certainly one of those days when you stand over it and you believe everything. My stroke just felt great and I felt convinced over the putt. I was into focusing on putting a great stroke than attempting to create it if you know exactly what I mean.
Cantlay surged into contention with an impressive back-nine – his first nine – using four birdies and an eagle-two at the driveable par-four 15th including around an inward 30, even though his scoring was more sedate on the front as he mixed two further birdies having a lone blemish.
The major quartet have a one-stroke lead over Australian Matt Jones, who returned with an eight-birdie 63, while Scotlands Martin Laird hurried to and capped a 65 that is stellar with his seventh birdie of the round.
Former Masters champion Adam Scott is also below, together with US Open holder Gary Woodland, Phil Mickelson and Bryson DeChambeau one farther.
But world No 1 Koepka is going to have the weekend after he was not able to coincide with the low scoring of his rivals, offsetting three birdies with a bogey and a double-bogey at the par-four 11th, where it shot him four shots simply to obtain the putting surface.
As the key winners younger brother Chase added a 69 to his opening 66 to finish off the lead on seven under 45, there will be attention for the Koepka family over the second half of the occasion.