Day satisfied with PGA return in Maui

A final-hole bogey left a sour taste in Jason Day's mouth, but overall the world No.1 rates his first US PGA Tour round in three months as "pretty solid".

Returning after rehabbing a bulging disc in his back that ended his last season, Day overcame signs of rust to shoot an opening three-under-par 70 that left him five shots adrift of leader Jimmy Walker at the 32-man Tournament of Champions in Hawaii.

Walker's bogey-free 64 gave him a two-shot lead over fellow Americans Jim Herman, Ryan Moore and Justin Thomas at Kapalua's Plantation course.

The 29-year-old Day shared 12th place with six others, including playing partner Patrick Reed and fellow Australian Aaron Baddeley.

"I had two three-putts and you can never have a three-putt. A bogey (with three putts on the par-5 18th) is obviously not the way I wanted to finish," said Day.

"But for the most part it was pretty solid."

Veteran Rod Pampling seized leading Australian honours courtesy of a satisfying four-under 69.

"It was a solid day of golf. We got pretty good conditions so it was good to get out there and hit it well. It was a good way to start the year," 47-year-old Pampling said.

Greg Chalmers rounded out the four-man Australian contingent - his 71 enough to share 19th with Charley Hoffman and Russell Knox at two under.

Tournament favourite and world No.5 Jordan Spieth suffered a lacklustre start to his title defence, signing for a one-under 72 a year after he gapped the field at Kapalua with 30-under total and an eight-shot victory.

The Tournament of Champions is an event for last year's tour winners without a halfway cut and a prize purse of $US6.1 million ($A8.3 million) event.