'I'm playing really well, I don't know what else you can say,' said Sheehan. 'I'm making a lot of putts inside the 15-foot range.'
Sheehan will take the lead into the final round for the second time in 2002. He held the 54-hole lead Virginia Beach Open but struggled to a 4-over 76 to tie for sixth.
The closest competitors to Sheehan are D.J. Brigman and Rob McKelvey, who share second place at 14-under par. Brigman carded a 3-under 69 Saturday while McKelvey came in at 2-under-par 70 and both know they will need help come Sunday if they are to visit the winner's circle.
'Nothing is fazing Patrick out there,' said Brigman. 'If I have to be a little more aggressive tomorrow to win then I'll have to do that. But you still have to play smart.'
'Patrick is going to have to have an off day for us to catch him tomorrow,' said McKelvey. 'You'll have to be aggressive tomorrow to win.'
Sheehan opened the round with a one-shot lead but quickly extended it. He birdied the first two holes and collected another birdie at the fourth when he drained a six-footer. He ran home a 12-footer for birdie at the sixth to make the turn at 4-under 32.
Sheehan racked up two early birdies on his back nine and grabbed a five-shot lead but dropped a stroke at the 17th. He rebounded with a tap-in birdie at the last to retain his five-shot edge heading into Sunday.
With a five-shot cushion, Sheehan knows that he can not afford to lose his focus if he wants to hoist the trophy.
'You can't put it on cruise control out here,' said Sheehan. 'I want my thought process to be the same tomorrow as it was today.'
Eric Meeks is alone in fourth place at 13-under-par, followed Brian Wilson (66), Scott Petersen (68), Jeff Freeman (70) and Todd Fischer (70), who share fifth at 12-under-par.
Full-field scores from the Ramey Price Cutter Charity Championship