Tom Kite, Des Smyth, Walter Hall, Allen Doyle, Dana Quigley and Morris Hatalsky finished tied for third at 4-under-par 66.
The start of the round was delayed with the course saturated by rain. When Wadkins finally took to the tee, he wasted no time before entering into red figures.
Wadkins started on the front side at Green Island Country Club with a birdie at the par-3 fourth. He added a birdie at the sixth and birdied the par-5 eighth to make the turn at 3-under.
The 51-year-old, who has three top-10 finishes so far this season, kept things going on the inward half with a pair of birdies from the 12th.
Wadkins jumped to 6-under with a short birdie at the par-3 17th but stumbled coming home with a three-putt bogey at the last to take the early clubhouse lead.
'I played well except the three-putt at the last hole,' said Wadkins, who has not won since his rookie season on the Champions Tour in 2001. 'It's extremely wet out there but the key is you need to keep it on the fairway.'
Dougherty played the back nine first and birdied the 10th to jump out of the gate. He picked up steam with back-to-back birdies starting at the 15th but found trouble with a bogey at the 17th to go out in 33.
He responded well with a birdie at the par-3 second and made it two in a row with a birdie at the very next hole. At the par-4 ninth, Dougherty knocked a 6-iron inside 15 feet for a closing birdie to join Wadkins in the lead.
'It was enjoyable to come back here to Green Island,' said Dougherty, a two-time winner on the Champions Tour. 'I made some nice putts today. Hit the ball well.'
Smyth also played the back side first and tallied two birdies and one bogey over his first nine holes. The Irishman carded three birdies on his second nine to finish one back of the leaders.
'I got off to a good start,' said Smyth. 'I'm happy with my round.'
Bob Gilder collected three birdies to go along with no bogeys for a round of 67. He was joined by Mike San Filippo, Tom Jenkins, Jim Thorpe, Larry Ziegler, Ed Fiori, Bruce Summerhays, Vicente Fernandez, Jerry McGee and Jose Maria Canizares in a tie for ninth at 3-under par.
Bruce Fleisher, Doug Tewell and Gary Koch were one shot further back in a group at 2-under-par 68.
Jay Sigel, who captured last week's Bayer Celebrity Pro-Am, was part of a group at 1-over-par 71.