Ryo Ishikawa joined Adam Scott at the top of the leaderboard at the World Golf Championships-Bridgestone Invitational, but a host of players, including World Number One Luke Donald, remained in close contention at Firestone Country Club.
Japanese teenager Ishikawa, who doesn’t turn 20 until next month, recorded birdies on the second - where he missed a short eagle putt - and third to reach 13 under.
That put him alongside overnight leader Scott, who also picked up a shot on the second, with Jason Day and Rickie Fowler two shots behind in a tie for third.
Fowler, like Ishikawa, was two under for his final round, having birdied the first and fourth. Day birdied the first but a three-putt bogey at the second saw him lose ground on the leaders.
Donald was a further shot back after a pitch to five feet set up a birdie at the first.
The Englishman’s playing partner Martin Laird three-putted the opener and immediately dropped from fourth to eighth. However, a birdie at the second lifted the Scot back alongside Donald and Keegan Bradley at ten under
Sweden’s Fredrik Jacobson remained nine under, one ahead of US Open Champion Rory McIlroy, who followed an opening bogey with birdies at two and four.
World Number Two Lee Westwood turned in 32 to climb into a tie for 11th at seven under.
Martin Kaymer and Justin Rose shot 67 to finish on one under and level par respectively, and Paul Casey matched their score to move to two over.
Former World Number One Tiger Woods could only muster a 70, however, and ended the week one over.