Luke Donald went to the turn in a spectacular 30 and led the Deutsche Bank Championship with seven holes to play in Boston.
Lying joint seventh entering the final round in the second of the FedEx Cup play-offs, England's World Number One had a hat-trick of birdies from the third, sank a 25 foot putt for eagle on the seventh and finished off the front nine with an eight footer for another birdie.
At that point Donald, runner-up in the same event last year, was being matched by playing partner Webb Simpson, but after both had gone over the green at the tenth the American was the one who failed to get up and down.
That put Simpson alone in second on 14 under, with Brandt Snedeker two back.
