Steven Alker, a New Zealander playing his rookie season on the Buy.com Tour, followed up a 7-under 65 with a 66 made up of four birdies and an eagle. He finished alone in second at 13-under, one shot ahead of Marco Dawson and Hunter Haas, who each shot 65.
Rob McKelvey, the winner here in 2000, carded a 67 for a share of fifth place at 11-under with Larry Rinker (66) and Bruce Vaughn (68). First-round leader Roland Thatcher posted a 71 to slip to eighth place at minus-10.
Raulerson collected seven birdies on the front side to go out in 29 -- his career-best nine holes -- then added birdies at the 11th and 12th to reach 16-under. But he double-bogeyed the 452-yard 13th, a hole dubbed 'Gator's Jaw', after he pushed his tee shot right into the water.
'I went against my judgment with the driver,' said Raulerson, 38. 'I wanted to hit it down there as far as possible and have a wedge into the green. I tried to cut a little driver and I cut it right into the water. It was just a mental mistake, no doubt about it. That one rattled me a little.'
He quickly rebounded with a birdie at the par-5 14th, but lipped out three birdie attempts over the final four holes.
Alker, who won twice on the Canadian Tour in 2000 on his way to that circuit's Order of Merit title, was the only player in the field to make it through 36 holes without a bogey.
'It was a good atmosphere out there,' said Alker, who has also won twice on the Australasian Tour. 'It's a frame of mind out there. You get a couple of birdies and you keep going.'
Dawson's round included seven birdies and an ace with a 7-iron at the 168-yard, par-3 eighth, the first hole-in-one on the Buy.Com Tour this year.
'I hit the ball worse today than I did yesterday, but I had a better score,' said Dawson, a PGA Tour veteran who played in the big leagues last year under a medical exemption after undergoing back surgery in 2000.
The cut fell at 6-under-par 138, the lowest mark on the Buy.Com Tour since last year's Permian Basin Open.
Full field scores from the Louisiana Open