Spieth held a share of the overnight light with Kirk and rookie Taylor Montgomery at the par-70 Waialae Country Club course in Honolulu, but while everyone was expecting the three-time major winner to take control of the tournament, both of his co-leaders would end up eclipsing him.
Spieth could only manage a five-over-par 75 after making no less than six bogeys, including four in a row during a horror run that started on the eighth hole.
Although darkness halted play with a handful of players still on the course, he looked certain to miss the cut.
"Just a bad day," Spieth said. "Didn't feel like it was much different. Made a couple bad swings from off the tee.
"Other than that, I didn't play that different. I just ended up a foot into the rough here, right behind a tree here, it was a weird, weird day."
In contrast, Kirk enjoyed serene progress, opening with three birdies and never looking back on the way to a well-played 65.
It's a great start to the year for a player who hasn't won in eight years and spent time away from the tour as he battled alcoholism and depression.
"I felt good going into today and after playing really well yesterday you want to come out and hit some solid shots and kind of ease into it," he said.
"I did not ease into it at all. Really nice putt I made on one, and then couple pitching wedges on two and three that I hit pretty close."
Montgomery is tied for second place with the in-form JJ Spaun after staying in touch of the leader with a four-under-par 66.
Spaun briefly held the lead but bogeyed his final hole to drop in a tie for second. He would still sign for an impressive 64, however.
"Just one bad swing," said Spaun. "I'm in a good spot going into tomorrow and the weekend."
"I definitely feel like I could win at any time. I hope to do that soon."