Getty Images

Phil Mickelson made PGA Tour Champions history this week in a win at the Charles Schwab Series at Ozarks National. Lefty carded a three-round score of 191 that tied for the lowest 54-hole score ever in his debut outing on the Champions Tour. He becomes the 20th player in the senior circuit's history to win in their debut. 

Mickelson's final score of 22 under was buoyed by an opening-round 61 in which he drained 11 birdies and paced the field early with what turned out to be the best round by any golfer in the field all week. Carding a 64 and 66 on Tuesday and Wednesday aided him in finishing off the wire-to-wire win with a four-stroke cushion over Tim Petrovic.

There was a question as to whether Mickelson would even compete on the Champions Tour this week after missing the cut at the Northern Trust last week.

"I really enjoyed playing here, enjoyed seeing the guys again, and they were so accommodating and fun, and it was just fun for me to compete," Mickelson said after the win. "I got to shoot scores and compete. The competition here was really strong. It was good for me to get off to a good start and compete."

Mickelson, a five-time major champion who turned 50 years old earlier this year, hasn't won a major since 2013 but is still respected as a threat at every level of championship golf. He finished T2 at the WGC-FedEx St. Jude Invitational in Memphis earlier this month and finished second at the AT&T Pebble Beach Pro-Am earlier this year. He's expecting to play in the U.S. Open in September.