Henrik Stenson carded a third-round 65 to earn a one-shot lead over Rickie Fowler heading into the final day of the Deutsche Bank Championship in Massachusetts.
The Swede boosted his hopes of a second FedEx Cup title in three years with a bogey-free round, encompassing four birdies and an eagle, to finish Sunday on 13-under-par.
One stroke back, a consistent Fowler shot a third successive 67 as the American stays in contention for a third PGA Tour title - and second in 2015, having won The Players Championship.
Matt Jones and Sean O'Hair will also bid to chase down Stenson on the final day, with the duo on 11-under, while Scotland's Russell Knox sits one shot back.
Hideki Matsuyama, Daniel Berger, Danny Lee, Kevin Chappell and Jerry Kelly finished the session on eight-under to harbour outside chances of success.
