Brendon Todd and Billy Horschel fired a six-under 66 for a four-way share of the second-round lead in the QBE Shootout.
The American duo sit on 19-under 125 alongside Rory Sabbatini and Kevin Tway (67), Harold Varner III and Ryan Palmer (70), Jason Kokrak and JT Poston (68) and Charles Howell III and Bubba Watson (66).
Ian Poulter and Graeme McDowell are just one shot further back in fifth after a seven-under 65 which contained seven birdies.
Todd and Horschel had six birdies in windy conditions in a flawless round in the modified alternate shot format at Tiburon Golf Club in Florida.
Todd, the FedEx Cup points leader after victories this season at Bermuda and Mayakoba, was paired with Horschel for the tournament when Brandt Snedeker withdrew because of an injured left ring finger.
"I knew when Brendon was going to be my partner when Sneds had to withdraw I got a better partner," Horschel said. "Sorry, Sneds, but Brendon's been playing really well, two wins, fourth-place finish. I was probably the happiest guy in the world at that point. I've known Brendon since college days, he's a great putter."
Todd added: "Billy's hitting the ball really well, we're both putting two shots in the fairway. The tricky part is you're not putting every hole, so to get the speed of the greens down is just tough out there, but I think we ham-and-egged it pretty good."
The tournament ends on Sunday with a best-ball round and it looks certain to be a competitive affair with another three pairs handily placed on 17 under.
However, Lexi Thompson and Sean O'Hair are out of contention in last place in the 12-team field at six under after a 74.
Watch the final round of the QBE Shootout live on Sky Sports Golf from 5pm on Sunday.