Greg Chalmers has produced his best round at Muirfield Village in 14 years, while Jason Day and Tiger Woods have battled to average scores midway through the opening round of the Memorial Tournament.

Chalmers put together a solid three-under-69 to be just two shots off the early pace, while Day could only muster a 72 and 14-time major winner Woods did extremely well to climb off the canvas and shoot 73.

Americans Ryan Moore, Brendon Todd, Harris English and Ken Duke all put up five-under 67s to take the early clubhouse lead while major winners Jordan Spieth, Justin Rose and Keegan Bradley were among the chasers just one shot back.

Chalmers, who was battling a stiff back, jumped out of the blocks playing the back side first with three birdies in his opening four holes.

It looked like he might waste the hot start when he was back at one-under through 13 holes but a couple more birdies ensured just his third round in the 60s at Muirfield in 29 rounds, the first since 2001.

Day, a member and local, struggled with the speed of the greens throughout his round and missed multiple birdie opportunities.

His only birdie on his opening nine holes, the back side of the course, came from a holed out bunker shot and then bogeys on the third and eighth holes after he made the turn had him staring down the barrel of an over-par start.

But a precision wedge to close range on his final hole ensured he would finish even.

Woods, a five-time winner of the event, blew out to four-over through nine holes but scratched his way back to just one-over with three birdies in his last eight holes.

Marc Leishman is the next best Australian, currently two-under through six holes while Matt Jones and John Senden carded rounds of 71.

Last start winner Steven Bowditch is even through three holes and Cameron Smith sits two-over through 17 holes.