(CNN) -- Tiger Woods faces a twin threat to his world number one spot heading into the final round of the Deutsche Bank Championship in Boston.
Either Phil Mickelson or fellow American Steve Stricker can end his five-year reign depending on their respective performances on Monday.
Current world number two Mickelson has his 10th chance this season to overtake Woods after a series of near misses.
A top-four finish, with Woods outside the top 24, will see him over the line but their are a series of other permutations, with Mickelson trying not think about the outcome.
"I haven't paid attention to what needs to happen, but I'm looking forward to getting in the hunt and seeing if I can get off to a good start and make some birdies," Mickelson told AFP.
Defending Deutsche Bank champion Stricker could also gatecrash the party.
He must retain the title at the $7.5 million tournament, which is part of the PGA Tour playoff series, while Woods finishes outside the top nine and Mickelson not in the first three.
Stricker is in fourth place, four shots behind leader Jason Day of Australia, after the third round, with Mickelson one further behind and firmly in the mix.
Woods carded a two-under par 69 on Sunday to continue his generally improved form but is sharing 23rd and needs a strong finish to protect his status and also impress U.S. Ryder Cup captain Corey Pavin.
"I played better than what my score indicated," Woods said after his round.
The tournament also is the last event before Pavin names his captain's picks on Tuesday for the U.S. team that will take on Europe next month in the Ryder Cup.
Woods is tipped to make the team despite his form slump this year in the wake of revelations which have led to his recent divorce from Elin Nordegren.