Theegala was one of the few players to have finished his first round on Thursday and so did not play on Friday as he waited for his Saturday start.
A three-and-a-half-hour rain delay on Thursday disrupted the schedule and then a frost delay on Friday added to the disruption.
The rest appeared to have done Theegala the world of good, however, as, after reaching the turn three-under, he went on a back-nine blitz.
It began badly with a bogey on the par-four 10th but then he made five birdies on the last eight holes to move to 13-under for the tournament, one shot clear of Andrew Novak and Canadian Nick Taylor, who shared the lead when darkness halted play Friday.
"It was such a weird feeling, like having a day and a half between rounds. I don't think that has ever happened with me," said Theegala.
"My driving has been so good to start the year and I just kind of kept it rolling.
"I had a really nice range session yesterday. I came to the course and just worked on some stuff with my coach for an hour. We were just like, get in, get out, don't waste too much energy."
There was no shortage of energy around TPC Scottsdale with a sold-out crowd and the traditional raucous crowds at the 'stadium' 16th green.
As the early cold weather eased into more pleasant conditions, it wasn't just the crowd that warmed up.
"I had some nice putts fall for me early on," said Theegala.
"The one (birdie) on two was big. Just to get something under par when the conditions were not good early was really a bonus and then just kind of kept it rolling from there."
Theegala had led at this stage two years ago before finishing tied for third after the final round.
Players were due back on the course to start their third rounds later on Saturday.
