Harris English pulled two strokes clear at the halfway mark of the Tournament of Champions as Dustin Johnson and Jon Rahm made their moves.
English, who shared the overnight lead with Justin Thomas, carded a six-under 67 in the second round in Kapalua, Hawaii on Friday.
The American produced a bogey-free round that featured six birdies to move into 14 under at the first PGA Tour event of 2021.
English is two shots ahead of Thomas (69), Daniel Berger (65), Collin Morikawa (65) and Ryan Palmer (67).
Thomas, a two-time champion of the tournament, made four birdies on his front nine but a bogey at 13 slowed his momentum before picking up another shot at the last.
The world's two top-ranked players, Johnson and Rahm, charged into contention.
Johnson, who opened with a 71, made eight birdies in a second-round eight-under 65 to get to 10 under – enough for a tie for 10th.
Rahm is alongside him after the Spaniard produced a fast finish, birdieing five of his final seven holes.
Xander Schauffele (66), Brendon Todd (67), Im Sung-jae (68) and Patrick Reed (68) are tied for sixth at 11 under.
Joining Johnson and Rahm at 10 under are Scottie Scheffler (66), Bryson DeChambeau (67), Joaquin Niemann (67), Carlos Ortiz (67) and Patrick Cantlay (68).