(Reuters) - American Jay Haas charged into early contention for a third Senior PGA Championship title by shooting a flawless five-under-par 66 in Thursday's opening round at Bellerive Country Club in St. Louis, Missouri.
The 59-year-old shrugged off lingering back pain with accurate driving and deft course management to end a cool, blustery day tied at the top with compatriot Duffy Waldorf, who qualified for the over-50 Champions Tour last August.
Japan's Kiyoshi Murota and American club professional Sonny Skinner started out with 67s in the first of the season's five senior majors, finishing a stroke in front of Taiwan's Lu Chien-soon and Australian Peter Senior.
Haas, a 16-times winner on the Champions Tour who clinched the Senior PGA Championship in 2006 and 2008, expressed both delight and surprise after his five-birdie display.
"Certainly very excited about shooting five under here," he told reporters. "Probably my lowest score ever at Bellerive, no matter what age I was. I didn't expect it going out.
"I wasn't very sharp today, but my misses were in the correct spots and I took advantage of a few good iron shots. I'm very, very pleased with that."
Asked how much he had been bothered by his back, St. Louis-born Haas replied: "A little bit. It's tight, it doesn't allow me to kind of stay in my spine angle. Just trying to hit the fairways was my first key and I did that a lot today."
A special bonus for Haas was being watched over the last nine holes by his 84-year-old uncle Bob Goalby, the 1968 Masters champion who had introduced him to the game.
"At 84, that's pretty impressive," Haas smiled. "The last time he walked nine holes I don't know when that was, but I was happy to see him.
"I have a picture at my house and it's of me and him and his caddie in the '65 (U.S.) Open here ... just walking off the 14th green. I was 11-years-old then. I said to my caddie, 'Here he is watching me play golf at 84 and I'm 59.' It's pretty cool."
Roger Chapman, who won last year's Senior PGA Championship by two shots over American John Cook before landing a second major crown at the U.S. Senior Open two months later, launched his title defense with a 72.
"I was a bit nervous," the 54-year-old Englishman said after mixing two bogeys with a lone birdie. "I got off to a shaky start. But I just sort of stuck in there, hung around.
"I didn't play great, sort of up-and-down a few times for pars. But overall 72, in the breeze today, wasn't too bad."
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Peter Rutherford)