Tiger Woods warms up for US PGA with eighth win in Ohio 8: Bradley (US), Stenson (Swe) 6: Johnson (US), Dufner (US), Jimenez (Spa), Selected: -5: Wood (Eng) 4: Donald (Eng) 1: Rose (Eng) World number one Tiger Woods warmed up for the final major of the year, the US PGA Championship, with a seven-shot win in the Bridgestone Invitational. Starting the final round seven shots clear, the American coasted to victory to secure his eighth title at Firestone Country Club in Ohio. Compatriot Keegan Bradley finished tied second with Swede Henrik Stenson. Woods, 37, starts his challenge at Oak Hill Country Club on Thursday looking for a first major win since 2008. Woods's major wins After Friday's career-equalling best 61, he looked content to cruise towards victory as he carded nine straight pars to remain 15 under. He registered his first birdie of the day on the 10th, holing from seven feet, and with Bradley dropping a shot on the 12th after a wayward tee shot, the lead was up to nine shots. He still had some way to go to match his record margin of victory, having won the 2000 US Open at Pebble Beach by 15 shots, and when Jason Dufner birdied the 13th the gap was back to eight. Woods three-putted the 14th for a bogey to finish with a round of 70, but the only real matter of interest by now was the battle for second place. Bradley gained the upper hand with a birdie from 20ft on the 17th to reach eight under, one shot ahead of Dufner and Stenson with former Masters champion Zach Johnson in the clubhouse on six under after a closing 67. Stenson then also birdied the 17th to tie with Bradley in second. Ryder Cup hero Martin Kaymer had gone one better with a 66, the former world number one recovering from an opening 74 with three rounds in the 60s to finish four under.