There was a weather delay that lasted close to an hour and play was suspended due to darkness. The first round will resume at 8:30 a.m. (ET) Friday morning with 11 players who did not finish on Thursday.
Brad Elder, Jaco Van Zyl, Greg Chalmers and Keoke Cotner are tied for third place at 5-under-par 67. Kris Blanks is 5-under par, but only played 15 holes on Thursday.
The two co-leaders got quite a look at each other's games since they were paired together on Thursday.
Staten wasted little time in breaking into red figures with a 15-foot birdie putt at the first. He hit a 7-iron to 10 feet to set up another birdie at the third.
He parred his next four holes then went on a birdie tear around the turn. Staten hit his rescue club off the tee at eight, then played a 9-iron to 20 feet for his third birdie of the round.
Staten made it back-to-back birdies thanks to a 30-footer at the ninth. He polished off three in a row with another long birdie putt, this time from 40 feet to reach 5-under par for the championship.
'It's been a long time since I've holed that many feet of putts,' joked Staten.
The putter turned balky on 13 when he three-putted for a bogey. Staten atoned for the error one hole later thanks to a two-putt birdie at the par-5 14th.
Staten holed one more long birdie putt, a 25-footer at 16 to grab his share of the lead.
'Today was a lot of fun,' said Staten, who has played four PGA TOUR events this season. 'It was just one of those days. It hasn't happened too often for me this year.'
Day, an Australian with two top-six finishes this season, birdied the first then sank a 6-footer for a birdie at two. It all came undone at three when his ball plugged and he two-putted from 12 feet. Day walked off with a double-bogey to move back to even-par.
He drained a 5-foot birdie putt at the sixth and added another from 10 feet at No. 8. Day ran home a pair of birdie putts in the 18-foot range at 11 and 12.
Day closed out his round in strong fashion. He converted a 12-foot birdie putt at the 15th and a five-footer at the 207-yard, par-three 17th to join Staten in the lead.
'It was a good day with the putter,' said Day, who has not made a cut in his last two starts. 'I was just trying to keep it cool...don't let the emotions run you over.'
Dustin Bray, who was the final member of the playing group that featured the co-leaders, shot a 4-under 68 and is tied for eighth place with Rich Barcelo, Esteban Toledo, Matthew Jones, Tim Wilkinson and No. 2 on the money list, Nicholas Thompson.
A busy GOLF CHANNEL will have coverage of all four rounds.