LAKE ORION, Mich. — Roger Chapman had a lot of thoughts running in his head as he closed in on the U.S. Senior Open title.

One of them was proving that his Senior PGA Championship victory wasn’t a fluke.

Chapman shot a 4-under 66 on Sunday to win the U.S. Senior Open by two strokes at 10 under at Indianwood. He won the Senior PGA Championship by the same margin two months ago on the other side of Michigan.

“I wanted to prove to myself and to other people that Benton Harbor wasn’t a one-off event,” he said. “That was in the back of my mind.”

Chapman kept his wits after a bogey at 16 gave big-name players on the Champions Tour — Corey Pavin, Tom Lehman, Fred Funk and Bernhard Langer — a chance to potentially catch him.

The 53-year-old Chapman, though, stepped to the potentially pivotal 195-yard, par-3 17th and calmly hit a 5-iron shot that was close enough for a tap-in birdie that restored a two-shot lead.

“I have to say that was my best shot ever played,” he said.

Langer (72), Funk (67), Lehman (68) and Pavin (68) finished tied for second at 8-under 272 at the Champions Tour’s fourth of five majors. Pavin’s two-stroke penalty after his first round for hitting a ball that moved a fraction of an inch proved to be costly.

By holding off senior stars, Chapman earned the right to be mentioned in the same sentence with Jack Nicklaus, Gary Player and Hale Irwin.

Not bad for a self-described former European Tour journeyman.

Chapman, Nicklaus, Player and Irwin are the only players to win the U.S. Senior Open and Senior PGA Championship in the same year.

“It’s a true honor,” Chapman said.