Jon Mills, Darren Beck, Tony Christie, Brent Schwarzrock and Peter O'Malley share second place at 6-under-par 66.
Just days removed from his breakthrough victory at last week's Jacob's Creek Open, Bowditch started on the back side at Clearwater Golf Club and parred his first three holes before running off back-to-back birdies from the par-4 13th under optimal scoring conditions.
Bowditch kept on rolling with a birdie at the par-3 16th and added a birdie at the par-4 17th to make the turn at 4-under. He continued his birdie barrage on the front nine with back-to-back birdies starting at the par-4 first.
The 21-year-old tallied another birdie at the par-5 fifth and reached 8-under with a birdie at the par-4 eighth.
O'Malley got into red figures with three consecutive birdies starting at the par-5 fifth.
The Australian, who captured this event in 2002, stumbled to a bogey at the par-3 11th but was able to recover with a birdie at the par-5 14th. O'Malley then birdied each of his last three holes to finish two shots off the lead.
Mills mixed seven birdies with a bogey for his share of second.
'I did a pretty good job of not worrying about what I was doing,' said Mills. 'I didn't get too excited.'
Bryce Molder collected five birdies on Thursday for a 67 to join Ken Duke, Jarrod Lyle, Jeff Gove and Steven Jeffress in a tie for sixth at 5-under par.
Ricky Barnes, the 2002 U.S. Amateur champion, was one shot further back along with Kris Cox, Kyle Thompson, Jason Schultz, Wayne Grady, Tyler Williamson, Johnson Wagner and Simon Nash at 4-under-par 68.