Durant, coming off a ninth-place tie Sunday at Shoal Creek in the first major of the year, missed only one fairway and birdied all the par 5s. He and also birdied the par-4 seventh hole that plays up a sand dune and usually into the wind off Lake Michigan.
Forsman, a three-time winner on the Champions Tour after winning five times on the PGA Tour, had four birdies and a bogey - on the seventh - in his final nine holes.
Faxon made two 35-foot birdie putts early in his round. He has only one top-40 finish in eight tournaments this year and missed the cuts in his two previous Senior PGA appearances.
Perry is trying to win his fourth consecutive Champions Tour major. He won the Senior Players Championship and U.S. Senior Open in consecutive tour starts last year, then skipped the Senior British Open.