An unheralded American pair top the leaderboard heading into Friday's second round, while Jordan Spieth is four shots back.
Emiliano Grillo remains the man to beat heading into Sunday's final round.
An eight-under 63 in the second round saw Emiliano Grillo surge clear at the Mayakoba Golf Classic.
Scottish golfer Russell Knox set the early pace at El Camaleon Golf Club on Thursday.
Tyrrell Hatton tops the leaderboard after one round of golf in Las Vegas, Nevada.
There is a log-jam atop the leaderboard heading into the weekend, while Bryson DeChambeau remains within striking distance.
Bryson DeChambeau continued where he left off on Thursday, setting the early pace in Las Vegas.
As Tiger Woods started well, Harris English is in a four-way tie for the lead at the Northern Trust.
Brooks Koepka and Jason Day are among those two shots behind US PGA Championship leader Li Haotong.
Brooks Koepka and Justin Thomas are among a fearsome chasing pack for leader Brendon Todd at the WGC-FedEX St. Jude Invitational.