Scottsdale - Tiger Woods admitted it had been "a grind" after he labored to a 73 on Thursday in the opening round of the Phoenix Open, his first full-field tournament of the season.
Ryan Palmer fired a seven-under 64 to lead the PGA Tour event at TPC Scottsdale, which is just down the road from where the Seattle Seahawks and New England Patriots will meet in Sunday's NFL Super Bowl spectacle.
But there was nothing spectacular about the form of former world number one Woods, who suffered a bad start and was left tied for 104th as play was suspended by darkness with nine players still on the course.
"Physically I am fine," said Woods, after starting his round with two bogeys, par, then double bogey.
"Mentally I am tired from the grind of trying to piece together a round. It takes lot of energy to be able to fight back like that."
Major champions Keegan Bradley and Bubba Watson share second place at six-under. They were joined by Daniel Berger, who was through 16 holes of round one. Berger will complete his first round on Friday morning.
Former Masters winner Zach Johnson carded a five-under 66. He was in fifth with Martin Laird, Robert Streb and Ben Martin.
Woods spent months recuperating from an ongoing back problem before taking part last month at the Hero World Challenge, his charity invitational event, in southern Florida. He shared last in a field of 18.
Woods is playing for the first time in an official event since last year's PGA Championship. He had back surgery last March.
Woods, a 14-time major winner, said he expects to have some off days while he adapts to changes in his swing that he hopes will eventually lead him back to his brilliant best.
"It is going to take a little time to get the feel of where my hands need to be during my swing and shaping shots," he said. "I have been through it before.
"It is a frustrating thing. I need to get into some competitive rounds and then I can start trusting it."
With Woods, the story is typically about his quest to match the career record of 18 major titles won by Jack Nicklaus.
This was the first tournament for Woods since turning 39 and no player has won more than three majors beyond his 39th birthday.
Woods was coming to Phoenix, known for a loud and boisterous crowd, for the first time since 2001, when a fan tossed an orange onto the green while he was putting and another who heckled him was later found to have a gun.
Phil Mickelson, a three-time winner of this event, also started slowly as he was three-over par through six holes, but he carded five birdies over the final 11 holes for a two-under 69. He is in a large group tied for 29th.Scores on Thursday after the first round of the $6.3 million Phoenix Open (par 71):
64 - Ryan Palmer
65 - Bubba Watson, Keegan Bradley
66- Zach Johnson, Martin Laird (SCO), Ben Martin, Robert Streb
67 - Justin Leonard, Angel Cabrera (ARG), Graham DeLaet (CAN), Brendon de Jonge (ZIM), James Hahn, William McGirt, Michael Thompson, Shawn Stefani
68 - K.J. Choi (KOR), Geoff Ogilvy (AUS), Rory Sabbatini (RSA), Aaron Baddeley (AUS), Jamie Donaldson (WAL), Freddie Jacobson (SWE), J.B. Holmes, Brian Harman, Jonas Blixt (SWE), Chris Stroud, Seung-Yul Noh (KOR)