The Tour's winners-only event in Maui welcomes only those players who have notched victories during the 2018 calendar year.
Meanwhile, defending champion Dustin Johnson was hit with a two-stroke penalty for hitting the wrong ball, leaving him with a double bogey.
Kevin Tway first played Kapalua as a 15-year-old a week before his father competed in the Sentry Tournament of Champions for the first time, an experience memorable for Bob Tway getting stung by a centipede and having to only watch.
Johnson and Thomas are the last two winners at Kapalua.
"With all the technical work I've done in the off-season it's a real contrast to come out here and completely forget about the swing and just hit the shot". I drove it well, kept the ball in play, hit a lot of greens and made some good putts. World number six Jon Rahm is tied for 11th at three under. "Each shot's hard so you're just focused on the trajectory and where I need to land it and where I need to miss it".
"I have a little different mindset this week, playing a little more aggressive, trying to contend, and trying to win instead of just enjoying the views out here, which I've done in the past", said Woodland.
It was the first tournament day where the players experienced the new rules introduced by the R & A and the USGA, with a few players choosing to putt with the flagstick left in, notably Bryson DeChambeau, an advocate of putting with the flag in place, who did it even from close range.
Kevin Na withdrew from the event before his scheduled tee time Thursday because of a fractured bone in his right pinkie finger.
World No. 1 Ariya Jutanugarn of Thailand will begin the 2019 LPGA campaign in two weeks with new caddie Daniel Taylor after a split with former bagman Les Luark.
Woodland, who has won three times in 231 starts on the PGA Tour, said his patience had been tested on a day that started extremely windy before abating somewhat as the leaders negotiated the back nine.