Morgan Hoffmann fired a 6-under 66 in Thursday's opening round of the Arnold Palmer Invitational and he leads by one stroke over five players.

Hoffmann is winless on the PGA Tour. He finished third at the BMW Championship last September for his best career finish.

Ian Poulter and Kevin Na both carded 67s on Thursday at Bay Hill Golf Club and Lodge. They were joined in second place at minus-5 by Ken Duke, Jason Kokrak and John Peterson.

Henrik Stenson and Adam Scott, world Nos. 3 and 4, shot 4-under 68 in the opening round. They share seventh place with defending champion Matt Every, Honda Classic winner Padraig Harrington, Hunter Mahan, Brandt Snedeker, 2011 winner Martin Laird, reigning FedExCup champ Billy Horschel, last year's runner-up Keegan Bradley, Ben Martin and Harris English.

World No. 1 Rory McIlroy, who is playing this event for the first time, posted a 2-under 70. He is among a large group tied for 32nd.