Tom Jenkins posted a 68 to finish alone in second place at 11-under-par 205. Doug Tewell and Jose Maria Canizares were three shots further back at 8-under-par 208.
Stadler continued his stellar play this week with his third consecutive win on the Champions Tour and seems to be a lock for Player of the Year honors.
I was in a pretty good mood today, said Stadler, who won for the eighth time on the Champions Tour. Im having fun playing golf again. Now Im in a comfort zone where I feel good and expect to play well.
He was scrambling early but managed to par his first three holes at Prestonwood Country Club until he knocked a 7-iron inside four feet for a birdie at the par-4 fourth. Stadler then three-putted for a bogey at the sixth, but played his tee shot to 10 feet for a birdie at the par-3 eighth.
Stadler picked up steam on the back side starting with a birdie at the par-4 10th after his second shot landed 11 feet from the hole. At the par-3 11th, Stadler hit his tee shot to eight feet and drained the birdie putt to make it two in a row.
The 51-year-old closed his round in style and dropped his approach inside 18 feet for a birdie at the par-4 16th. Stadler then birdied the 17th and hit a 9-iron within 10 feet of the hole for a birdie at the par-4 last to complete the runaway win.
I made some good putts, said Stadler. I came here thinking I could win or be right there.
Jenkins found trouble out of the gate with a bogey at the second, but he collected birdies at the seventh and the ninth to make the turn at eight- under.
The 56-year-old had no chance of catching Stadler, but Jenkins made a move on the back side to secure second place alone. He tallied a birdie at the par-4 14th and ran off back-to-back birdies from the 17th to finish six shots off the pace.
I knew I was playing for second, said Jenkins. But I was happy with my game.
Larry Nelson, John Harris and Lonnie Nielsen tied for fifth place at 7-under-par 209. D.A. Weibring, who won this event last year, joined Wayne Levi and Walter Hall at 6-under-par 210.
Allen Doyle and Mike Reid shared 11th place at 5-under-par 211.