Dustin Johnson drives par 4 with an iron

American golfer Dustin Johnson made a mockery of the fourth hole at the Deutsche Bank Championship driving the 289-yard hole with a 2-iron.

Johnson went on to two-putt for birdie as part of hot start in Boston where he birdied three of his first four holes.

It was the highlight of Johnson's opening round where he finished with a one-under 71 in a tie for 26th.

Australians Jason Day (-3) and Matt Jones (-4) are in the hunt after first round.  Brendon de Jonge (-6) leads the tournament.