Kevin Johnson, Darron Stiles, Todd Bailey and Brent Winston finished tied for sixth at five-under-par 67.
Baddeley began his round on the back side at The Golf Club at Yankee Trace and quickly made his charge with a birdie and an eagle over his first three holes.
He ran into trouble with a bogey at the 16th to make the turn at minus-two but recovered with a birdie at the par-five first.
After his second dropped shot of the day at the par-three third, Baddeley made the first of four straight birdies at the fifth to join the logjam atop the leaderboard.
'I'm starting to feel more comfortable out here,' said Baddeley, who finished third at the Arkansas Classic in April. 'It was a bit annoying to three-putt twice on the front nine but a lot of mistakes are three-putting these days. That's fine, because I'm normally a good putter. It's just a matter of time before they start dropping, or that's the way good putters think.'
Baddeley won back-to-back Australian Opens, the first as an amateur in 1999. He also captured the European Tour's Greg Norman Holden International in 2001 after beating Spain's Sergio Garcia in a playoff.
Kribel also started at the 10th and played a bogey-free round for his share of first. The 25-year-old collected two birdies over his first nine holes and added an eagle and two additional birdies on the inward nine.
'I was never really in any danger of making a bogey today,' said Kribel, who lost in a four-way playoff at last week's Hershey Open. 'When you have to scramble, it takes a lot of energy. There are a lot of good opportunities out there to make birdie.'
Buha was as impressive with a flawless round of his own. Buha had six birdies and no bogeys in search of his first Buy.com Tour win.
Barranger opened his title defense at a blistering pace with four consecutive birdies starting at the 10th. He bogeyed the 17th but countered with a birdie at the following hole to make the turn at minus-four under windy conditions.
'The wind is completely opposite what it was here a year ago,' said Barranger, who matched the Buy.com Tour record for lowest score in relation to par with a 26-under-par 262 total at this event last year. 'The birdies are out there but the course is really firming up and getting fast.'
He collected birdies at the first and third holes and took sole possession of first place with a birdie at the par-five sixth to reach seven-under. However, Barranger faltered with a bogey at the very next hole to fall back into a tie for the lead.
Full-field scores from the Dayton Open