Theegala was seven-under through 16 holes on Thursday when play was suspended due to darkness.

He returned to TPC Scottsdale on Friday and closed his promising first round with back-to-back bogeys.

However, his second round of eight birdies and just one bogey propelled him to 12-under 130, two strokes ahead of defending champion Brooks Koepka and Xander Schauffele.

Patrick Cantlay is alone in fourth at nine-under.

Koepka carded his second straight 66 while Schauffele made four birdies on the front nine en route to a bogey-free 65.

"Striking it good, maybe lost a little bit of speed there on a few putts," Koepka said.

"But the greens they're getting fast, they're getting firm. It will be interesting to see what they're like tomorrow."

Cantlay, like Schauffele, also kept bogeys off his card and shot a 66.

"I drove the ball and putted really well today," Cantlay said.

Theegala's 64 was tied for the low round of the day with Talor Gooch and Sam Ryder.

Gooch is tied for fifth with Max Homa (65) and Canada's Adam Hadwin (68) at 8 under.

Ryder is tied for 13th at six-under.

Adam Scott is the pick of the Australians but a one-under 70 dropped him back to a share of 34th at four-under par while Matt Jones (69) had an eagle two on his card as he made the cut on the number at two-under.

Among those that won't be playing on the weekend are Australian trio Lucas Herbert, Cam Davis and Craig Hocknull, and Norway's World No.3 Viktor Hovland.

Despite his bogey-bogey end to his opening round, Theegala maintained his positive mindset to propel his play on day two.

"I wasn't too upset about the way (the day) started," Theegala said.

"Like I had a 15-footer to start the day, so I was like, 'OK, I just put a good roll on it and see what happens'.

"I put a good roll, just missed.

"And the next tee shot I put it under the lip of the fairway bunker and I'm like, 'OK, I can't do much about that, right?'

"And I knew if I kept putting the ball in the fairway I'm going to have scoring opportunities, so it was nice to reset for the 30 or 40 minutes that I had in between the rounds there."

Theegala, a three-time All-American in college, is playing the event on a sponsor's exemption.

His only career top-10 finish, a tie for eighth, on the main Tour came last October.

Theegala is aiming to become the fifth player since the start of the 2014-15 season to win an event after entering on a sponsor's exemption.

"Just thankful that I'm here and trying to make the most out of the opportunity," the 24-year-old said.

"No expectations at all, honestly."