Stuart Appleby is just one shot off the lead after the first day at the Bridgestone Invitational at Firestone Country Club. On a day when most players found the going difficult on the back nine, Hunter Mahan, Paul Casey and Rory Sabbatini all made the most of impressive front nine efforts to lead the field after carding 3-under-67s. However the leading trio is just one stroke ahead of a six strong group on two-under which includes Appleby and world number one Tiger Woods. The round started brilliantly for Mahan who posted his second consecutive first round leading score after carding a course record nine-under-62 at the Canadian Open last week. Mahan produced five birdies to open and would have been outright leader but for a double bogey on 18 which saw him slip back to the field. Sabbatini had a similar round, posting six birdies on his front nine before dropping off coming home, while Englishman Paul Casey bucked the trend by posting a birdie on 18 to take his place at the top of the leaderboard. Appleby, meanwhile, enjoyed a reasonably consistent round, picking up two shots going out before being even on the back nine to be just one stroke off the pace alongside Woods. The closest other Australians to Appleby are Peter Lonard on an even par 70 and Aaron Baddeley, who carded 70 as well in a frustrating round that saw him post four birdies and four bogeys. John Senden (71) is just one stroke further back alongside New Zealand&aposs Michael Campbell and Aussie Rod Pampling. It was a particularly disappointing day for the in-form Campbell though as his five birdies were more than countered by three double bogeys. Pampling also had double bogey trouble on the back nine, but the Australian is still in contention, one stroke ahead of Nick O&aposHern (72) and two ahead of Geoff Ogilvy, Mark Hensby and Richard Green who all posted 73s. However, as the leading scores have been relatively high, Adam Scott (75) and Robert Allenby (76) also remain in contention to take the tournament. First Round of the World Golf Championships-Bridgestone Invitational: -3 Hunter Mahan 67, Paul Casey 67, Rory Sabbatini 67 -2 Mark Calcavecchia 68, Tiger Woods 68, Stuart Appleby (Australia) 68, Boo Weekley 68, Lee Westwood 68, Arron Oberholser 68 -1 Kenny Perry 69, Justin Rose 69, Chris DiMarco 69, Paul Goydos 69 E Peter Lonard (Australia) 70, Carl Pettersson 70, Darren Clarke 70, Steve Stricker 70, Scott Verplank 70, Ernie Els 70, Aaron Baddeley (Australia) 70 also: 1 John Senden (Australia) 71, Michael Campbell (New Zealand) 71, Rod Pampling (Australia) 71 2 Nick O&aposHern (Australia) 72 3 Geoff Ogilvy (Australia) 73, Mark Hensby (Australia) 73, Richard Green (Australia) 73 5 Adam Scott (Australia) 75 6 Robert Allenby (Australia) 76