The golf world number one Jason Day is losing his grip on the PGA Tour's $16 million play-off bonus as Henrik Stenson took command at the Tour Championship in Atlanta.
Day struggled to a one-over 71 to drop to even-par for the season-ending tournament, leaving the Australian a distant nine shots adrift from the Swede in a tie for ninth.
Stenson, who is guaranteed the massive payout if he wins the tournament, shot 68 to sit at the top of the leaderboard at nine-under, three shots clear of former No.1 American Jordan Spieth.
New Zealander Danny Lee slipped to a share of 13th following a second round 2 over par 72.
He's 1 over for the tournament, 10 shots behind Stenson.
Spieth made his move with a sublime 66 in tough wet conditions while England's Paul Casey (70) is third a shot further back.
British Open winner Zach Johnson (70) sits fourth while Australian Steven Bowditch continues to match it with the big guns after a 69 left him tied with Rory McIlroy (71) in fifth at three-under.
"It is very difficult to shoot a score out there if you are not hitting the fairways and I was just a little flat I guess you would say, not as sharp with the irons, not as sharp with the driver," Day said.
"Putts aren't quite going in as they were over the last seven or eight tournaments."
Day is also in danger of losing his world No.1 status after just one week.
Both Spieth and McIlroy can take the mark back if they win.
Spieth can be No.1 with a win and Day outside the top five, McIlroy takes top spot back with a win and Day outside the top 15.