Northern Trust: Russell Henley leads Dustin Johnson after first round

Russell Henley is ranked 56th in the world

Russell Henley holds a one-stroke lead from fellow American and world number one Dustin Johnson after the first round of the Northern Trust.

Henley, 28, shot three birdies in his first six holes on his way to a six-under-par 64 in Old Westbury, New York.

Johnson only dropped one shot in the first of the PGA Tour's four FedEx Cup play-off events, as defending champion Rory McIlroy carded a three-over 73.

"I hit a lot of really good shots," said Johnson, 33.

"I drove it well, did everything really well. It's the first time in a long time I've done that."

Johnson retains the top spot despite struggling to find the form that resulted in three victories heading into the Masters in April, when he was forced to pull out after slipping and injuring his back on the eve of the tournament.

"Today was the first time it's kind of felt - the golf swing - I was in control, like I was leading into the Masters," he added.

Justin Rose finished the day on two under par, while fellow Englishman Paul Casey and Martin Laird of Scotland are a stroke further back.

Northern Ireland's Rory McIlroy is nine shots off the pace after a disappointing three-over-par 73.