Chris Kirk, Billy Horschel lead the way in Georgia

Chris Kirk and Billy Horschel have both carded an opening-round 66 to share the lead at the Tour Championship in Atlanta tonight.

Both players shot bogey-free rounds and sunk four birdies apiece as the pair finished up on four-under-par after day one in Georgia.

Bubba Watson looked poised to join the duo on four-under, but a bogey at the last saw the two-time Major winner finish a stroke back.

Instead, Watson joined Patrick Reed, Jason Day and Jim Furyk in a four-way tie for second place.

Rory McIlroy ended up on one-under after shooting an erratic first-round 69 to leave him three shots off the pace.

A mixed front nine saw McIlroy record three birdies and two bogeys, before the four-time Major winner settled down and shot steady pars in seven of the back nine holes.