Jon Rahm shot a five-under 66 at TPC Boston to grab a two-shot lead at the halfway mark of the Dell Technologies Championship.
Rahm's round was highlighted by an eagle on the par-five 18th hole, while he also had six birdies, a bogey and a double bogey as he moved into nine under.
Adam Hadwin, Paul Casey, Kevin Streelman and Kyle Stanley all finished the day tied for second at seven under.
Hadwin, Casey and Streelman each shot six-under 65s in round two, while Stanley carded a 68.
The tight leaderboard also consists of four players at six under, led by Phil Mickelson, who shot a four-under 67.
Jordan Spieth and Justin Rose led a group at five under after shooting 65s on Saturday. Spieth finished his round with three birdies in his last four holes.
Dustin Johnson had two doubles bogeys on the back nine, leading to a one-over-par round. He is still in contention at four under, but will have to pass a lot of players to earn his second straight win.
Justin Thomas (67), Patrick Reed (67) and Louis Oosthuizen (69) are also at four under for the tournament.
Adam Scott and Rory McIlroy failed to make the cut, finishing their first two rounds at four over.
The season is now over for Scott, who will not make it inside the top 70 in the FedEx Cup standings.
Scott's fellow Australian Jason Day made it to the weekend after a two-under 69 left him at two over.