Couples, who won the 2011 Senior Players Champions in a playoff, tied the 18-hole tournament record Friday and beat the 36-hole record by two strokes. He had eight birdies and one bogey in his 63 and is at 11-under 129 for a one-stroke lead over Joe Daley, who was 6-under Friday.
First-round leader Bruce Vaughan was 4-over Friday and dropped into a tie for 17th at 2-under for 36 holes.
Couples had a bogey-free 4-under 66 Thursday and jumped up the leader board with four birdies in his first six holes Friday. He had a 5 at the par-4 12th but rebounded with a birdie at No. 13.
A string of birdies over 15-17 allowed him to pull clear and set the 36-hole record.