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. 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. 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. By holding off senior stars, Chapman earned the right to be mentioned in the same sentence with Jack Nicklaus, Gary Player and Hale Irwin. Roger Chapman kisses the Francis D. Ouimet Memorial Senior Open Championship Trophy after winning the U.S. Senior Open at the Indianwood Golf and Country Club in Lake Orion, Mich., Sunday, July 15, 2012. Player was the first to win the U.S. Senior Open and Senior PGA Championship in the same year back in 1987. Nicklaus did it in 1991, and Irwin pulled off the feat in 1998. Until Chapman's breakout, his shining moment was beating Padraig Harrington in a playoff for his first European Tour win in his 472nd start on that tour. The Englishman had a conditional exemption on the Champions Tour in 2010 and lost his status last year, finishing 84th on the money list at less than $90,000 after failing to crack the top 10 in any of his 11 starts. Chapman received $500,000 for winning the U.S. Senior Open after getting a check for $378,000 for the Senior PGA victory. "I guess when you read about him, you always hear journeyman or something like that," Pavin said. But he's always been a very solid player. Sometimes, people bloom a little later. The German said on Saturday if he closed with a 2- or 3-under round, it would be difficult for anyone to catch him. When Langer had a double bogey at No. "I knew there was a lot of golf left, and I was still in the lead," he said.