Dustin Johnson threatened the lowest round in PGA Tour history on his way to opening up a two-shot lead in an incredible second round at The Northern Trust.
Two eagles and seven birdies saw Johnson 11 under for the day after just 11 holes of his second round on a low-scoring day at TPC Boston, where Scottie Scheffler had set the clubhouse target after registering only the 12th '59 round' ever recorded on the PGA Tour.
Johnson required just one birdie over his final seven holes to match Scheffler's total and see two sub-60 rounds recorded in the same day for the first time ever, only to close his day with seven straight pars and post a 11-under 60.
After rolling in from 10 feet at the first, Johnson drained a 40-foot eagle at the par-five next before following a 20-foot birdie at the third by driving the par-four fourth green and setting up a five-foot eagle.
Johnson converted from 15 feet to birdie the fifth and go seven under for his round but temporarily saw his run halted with a two-putt par at the sixth after hitting his tee shot into the fairway bunker.
A tap-in birdie at the seventh and a six-footer at the par-three next took him to nine under for the day, with Johnson equalling the lowest front-nine in PGA Tour history despite only making a par at the ninth.
Johnson's incredible burst continued as he made a 15-foot birdie at the 10th and holed from 10 feet at the 11th move 11 under for his round, increasing the possibility of the first '57 round' being recorded on the PGA Tour.
The former world No 1 scrambled to make an eight-footer to save par at the next and failed to convert a 12-foot birdie attempt at the 13th, before settling for two-putt pars over his next three holes and missing an opportunity from 10 feet at the par-four 17th.
Needing an eagle at the par-five last to match Jim Furyk's all-time low score of 58, Johnson elected to lay up after missing the fairway and then pitched his third shot to 25 feet before two-putting for another par.
Scheffler had birdied four of his last five holes to become only the 11th player ever to shoot a sub-60 score on the PGA Tour, taking him to 13 under, with overnight co-leader Cameron Davis alongside him after following his opening-round 64 with a six-under 65.
Danny Lee and Harris English share fourth spot with Louis Oosthuizen, who posted a bogey-free 65, with Kevin Kisner a further shot back in a share of seventh alongside Russell Henley.
Ian Poulter, needing a strong performance to break into the top-70 in the FedExCup standings and extend his season, carded a four-under 67 to sit in tied-12th and within six of the lead.
FedExCup leader Justin Thomas is in the group on seven under that includes Tommy Fleetwood, with world No 1 Jon Rahm a further shot back after a four-under 67.
Rory McIlroy, Tiger Woods and defending champion Patrick Reed all made the cut on the number at three under, while PGA Champion Collin Morikawa and Bryson DeChambeau both failed to progress to the weekend.
Will the low scoring continue over the weekend? Watch live coverage of The Northern Trust on Saturday from 7pm on Sky Sports Golf and 7.30pm on Sky Sports Main Event.