The start of the second round was delayed two hours due to fog. That delay ultimately forced the suspension of play due to darkness.
Eighteen players will resume their second round at 7:30 a.m. (ET) Saturday. The third round will then begin approximately one hour after round two's completion.
Mike Grob notched his second straight round of 4-under 68. He stands alone in second at minus-8. Rob Oppenheim (70) and Matt McQuillan (68) are tied for third place at 5-under-par 139 with Paul Danielson and Michael Harris one stroke further back at minus-4.
Hultman opened on the back nine with a pair of pars. He dropped a shot at the 12th, but came right back to birdie the 13th on the Wild Bluff Golf Course at Bay Mills Resort & Casinos.
The Swede birdied 15 and 16 to move to 7 under. Hultman parred his next four holes before slipping to another bogey at the third.
Hultman climbed into the lead at minus-9 as he birdied five, seven and nine to close out his round.
'My putter has been the difference this week,' said Hultman, who has needed just 50 putts through two rounds. 'I've been getting great reads and making everything. I'm going to have to keep rolling it well all weekend.'
Tele Wightman, Peter Wilson, Peter Tomasulo, Kent Fukushima, Scott Gibson and Dave Levesque share seventh place at 3-under-par 141.
First-round leader Alex Rocha struggled to a 4-over 76 Friday and fell into a tie for 13th place at minus-2.