Argentina’s Angel Cabrera surged up the leaderboard as defending champion Keegan Bradley wasted no time in making a move when the second round of the WGC-Bridgestone Invitational got under way.
Two-time Major winner Cabrera was four under through 12 holes to get back to two under for the week – four shots behind the leaders.
Bradley began the day two shots behind overnight leader Webb Simpson but birdied his first two holes to join the former US Open Champion on six under par.
Starting from the tenth, former US PGA Champion Bradley holed from 20 feet for birdie and repeated the trick from 12 feet on the next before a run of four straight pars.
Simpson was among the later starters along with Open Championship runner-up Henrik Stenson, five under after a flawless opening 65, and World Number One Tiger Woods.
Woods, seeking an eighth win at Firestone Country Club, was four under after a 66 matched by fellow American Ryan Moore and England's Chris Wood.
World Number Three Rory McIlroy, looking to replicate the fifth place finish of last year which kick-started his season, had bogeyed the last in a first round of 70 and remained level par for the tournament after nine holes.
McIlroy began from the tenth and opened with four pars before a double bogey six on the 14th, where a drive into heavy rough meant the Northern Irishman needed three shots to get himself out of trouble.
However, the 24 year old had bounced back after a double bogey on the tenth yesterday and did the same again now, holing from three feet on the par five 16th and 15 feet on the 17th for birdies.
Bradley, who has been paired with Woods and former Ryder Cup Captain Davis Love III for the first two rounds of next week's US PGA Championship, birdied the 18th to reach the turn in 32 and claim the outright lead.
And another birdie on the par five second gave the American a two shot lead over Simpson, who was still an hour away from beginning his second round.
McIlroy had dropped back to one over par after a string of pars was followed by a bogey on the fifth, where he failed to get up and down from just short of the green.