Casey fired a six-under 65 on the Copperhead Course at Innisbrook Resort, safely negotiating the Snake Pit to set the clubhouse target at 10 under.
Reed moved alongside Casey but bogeyed the last to slip into a share of second alongside Woods, who closed with a one-under 70 to secure his best PGA Tour finish since 2013.
Masters champion Sergio Garcia matched Casey's joint-low round-of-the-day to end the week in fourth, with Justin Rose slipping down the leaderboard on the back nine to finish tied-seventh.
More to follow…
