World number one Tiger Woods fired a nine-under par 61 on Friday to seize a seven-stroke lead after the second round of the World Golf Championships Bridgestone Invitational.
Woods, playing his final tuneup for next week's last major tournament of the year at the PGA Championship at Oak Hill, fired an eagle and seven birdies to finish 36 holes on 13-under 127.
England's Chris Wood and American Keegan Bradley shared second on 134 after each fired a 68 on at Firestone Country Club.
Sweden's Henrik Stenson and American Bill Haas are fourth on 135.
Woods, a four-time winner this year and a seven-time champion in his career at Firestone, opened with birdie and then eagled the par-5 second and birdied the third.
After a birdie at the par-3 seventh, Woods caught fire with a run of four gains in a row to open the back nine and was in the hunt to break the PGA record low score of 59 before settling for pars on each of the final five holes.