Langer had a bogey-free round at Prestonwood in the regular-season finale. The 59-year-old German star leads the tour with four victories and earnings of $2,512,659. He won the 2012 event and tied for third the last two years.
Larry Mize and first-round leader Doug Garwood were tied for second at 8 under. Mize had a 69, and Garwood followed his opening 65 with a 72.
The top 72 players on the money list after the tournament - and one player in the top 10 in the event but outside the top 72 for the season - will get spots in the Charles Schwab Cup Playoffs opener - the PowerShares QQQ Championship at Sherwood in Thousand Oaks, California, on Oct. 28-30.
Defending champion Tom Lehman was tied for 10th at 4 under after a 68.