Miami - Bubba Watson and Charles Howell III produced a late birdie spree to join a five-way tie at the top of the leaderboard on Saturday at the QBE Shootout in Florida.
Watson and Howell nailed back-to-back birdies on the 17th and 18th holes to card a six-under-par 66, leaving them on 19 under heading into Sunday's final round at Tiburon Golf Club in Naples.
In-form Brendon Todd and partner Billy Horschel also finished the day in the leading group after a bogey-free 66 in a second round played under the tournament's modified alternate shot format.
Kevin Tway and Rory Sabbatini, meanwhile, finished with five-under-par 67 to join the leaders along with J.T. Poston and Jason Kokrak.
Overnight leaders Harold Varner III and Ryan Palmer, who had electrified the tournament with a 55 on Friday, had a more subdued second round with a two-under-par 70.
That score ensured they remained in the leading group however.
European stars Ian Poulter and Graeme McDowell are one back from the lead after a seven-under-par 65.
Poulter and McDowell's blemish-free round included a run of four birdies in five holes just before the turn, while three more birdies down the stretch left the duo well-positioned to challenge the leaders on Sunday, when the format switches to better ball.