Forsman got up and down for birdie on No. 14 to push his lead to three strokes. He closed with four consecutive pars to wrap up his round.
He ended his third Champions Tour victory at 15-under-par 201.
Jay Don Blake had a bogey-free, five-under 67, including a birdie at the last, to end alone in second place at 13-under-par 203.
John Cook, the 2011 winner, posted a four-under 68, while Michael Allen managed a three-under 69. They shared third place at minus-12. Gary Hallberg (66) and Jeff Sluman (71) tied for fifth at 11-under-par 205.
MORE TO FOLLOW.