England's Justin Rose hit an eight-under 63 to give him the first-round lead at the BMW Championship at Cog Hill, Illinois.
Should Rose win the tournament, he would be in contention at next week's tour finale at East Lake to win the FedExCup and the $10m (£6.3m) bonus.
The 31-year-old finished two shots ahead of Webb Simpson and Mark Wilson, with KJ Choi two shots further back in fourth.
Meanwhile Rose's fellow Englishman Luke Donald had less success, as the world number one hit a disappointing four-over 75.
