Jerry and Wesley Pate are in second place after an 11-under-par 61. Bob and David Charles are in sole possession of third place at minus-10.
This is a unique event in golf reserved for fathers who have won major championships and their sons. This year there are two exceptions as Arnold Palmer is once again playing with his grandson Sam Saunders and Lee Janzen is playing with Aaron Stewart, the son of the late Payne Stewart.
Saturday's action was in a scramble format, while better-ball is on tap for Sunday.
The Nelsons birdied three of their first four holes Saturday, then Larry chipped in for birdie at the fifth. They combined for a birdie at the seventh, then Drew ran home a 20-foot birdie putt at the eighth.
The Nelsons started the back nine exactly the way they started the front side. They tallied three birdies in their first four holes, then birdied No. 16 to reach 10 under par for the tournament.
At the 528-yard closing hole, Drew hammered his drive in the fairway, then hit a 9-iron to 3 feet. He tapped in the eagle putt to take his family into the lead.
'We drove the ball really well today,' said Larry. 'Drew drove the ball very well today. Our goal was to get into double figures today. We did have an enjoyable day today.'
The Pates recorded five birdies on the front nine, then wasted little time on the second nine. Jerry sank a 15-foot birdie putt at the 10th, added a 10-footer three holes later.
They made birdie at the 15th, then the son took over. Wesley hit a 5-iron to 20 feet with his second shot at the par-5 16th, and converted the eagle putt.
The elder Pate two-putted for birdie from 30 feet at the last to get the duo into sole possession of second place.
'Wesley played spectacular,' said father Jerry. 'We got off to a good start. This is our eighth year and this was one of our better starts. Wesley really hit the ball well and he putted really well.'
Tom and David Kite, Raymond and Raymond Floyd, Jr. and Bernhard and Stefan Langer are tied for fourth place at 9-under-par 63. Janzen and Stewart and Bill and Ben Rogers are knotted in seventh at minus-8.
Palmer and Saunders, Dave and Ron Stockton and the defending champions, Hale and Steven Irwin, share ninth place at 7-under-par 65.
Vijay Singh, the No. 1 ranked player in the world, and his son Qass shot an opening-round 66 and are tied with Curtis and Thomas Strange and Lee and Rick Trevino. That trio is tied for 12th place.
Lanny and Travis Wadkins and Craig and Chris Stadler share 15th at 5-under-par 67.