American Shawn Stefani carded a six-under 65 to take a two-shot lead after the first round of the Tampa Bay Championship on Thursday as Australian Geoff Ogilvy finds himself just four strokes off the pace. However the day belonged to Stefani as the PGA Tour rookie struck six birdies in a bogey-free round to lead from compatriot Brian Harman at the Innisbrook Resort in Palm Harbor, Florida. Harman rolled in five birdies and picked up a solitary bogey on the par-four ninth hole to sit in outright second on four under. A group of three Americans – Tag Ridings, Brendan Steele and Harris English – trail a shot further back in a share of third place. Major winners Vijay Singh and Ogilvy are part of an eight-way tie for sixth place on two under. Fijian Singh drained four birdies but was hampered by dropped shots at six and 13, while Ogilvy carded three birdies, an eagle and three bogeys in a topsy-turvy round. Defending champion Luke Donald sits a shot back on one under, where he is joined by the likes of American Nick Watney and Australian trio Adam Scott, Marc Leishman and Jason Day. Day was at one over heading into the last five holes but produced two birdies to finish with his one-under 70, while Leishman and Scott also endured inconsistent rounds as both players combined four birdies with three bogeys. Greg Chalmers and John Senden are a further stroke back at even par, although Chalmers could have been tied with Ogilvy had he not bogeyed his final two holes on Thursday. Further down the leaderboard, Aaron Baddeley is at one over, while Scott Gardiner and Steven Bowditch are a further stroke back. Matt Jones and Stuart Appleby will have plenty of work to do after opening with three-over rounds on Thursday, while Robert Allenby (four over) is a further stroke back as Cameron Percy and Alistair Presnell find themselves 12 strokes off the lead.