Tom and Eric Weiskopf took third place at 17-under par while last year's runner-ups, Johnny and Scott Miller, came in fourth at 16-under.
The Floyds made up ground early against the Irwins with six front-nine birdies. They birdied the par-4 11th and tied for the lead after a birdie at No. 13.
'That's when we thought we had a chance,' said Raymond Floyd. 'But we knew we would have to continue to make birdies because the Irwins and the Weiskopfs were playing behind us.'
Raymond and Robert combined for three birdies in a row, starting at 15, to pull ahead of the Irwins and despite a late birdie by Hale and Steve, the Floyds held on for the fifth victory for the family.
'You just can't expect to make up four strokes against these teams in a scramble format,' said Floyd. 'We thought two things would have to happen. We thought we would have to get to 22-under and we needed the wind to blow.'
The Floyds earned the $200,000 first-place check and Robert acknowledged that there is no pressure on him to join his brother as a three-time winner of this event.
'We're family,' said Robert, whose brother, Ray, Jr., won this title with the elder Ray three straight years from 1995-97. 'The Floyds own five of them.'
Larry and Josh Nelson came in fifth place at 16-under 128, followed by the Stadlers, who were a shot behind at minus 15.
Dave and Ron Stockton and Hubert and Myatt Green shared seventh at 14-under-par 130.
Jack and Jackie Nicklaus as well as Jerry and Wesley Pate withdrew before the tournament started due to injuries suffered by the fathers.