Read more: Rory McIlroy says he can win green jacket at US Masters

Rory McIlroy at 12 under leads the US masters championship after the third round by four shot from his nearest rivals.

While several players made runs at the lead McIlroy stayed remarkably cool on a boiling hot day in Augusta and fended off all challengers and extended his lead to four strokes with two key birdies on the back nine.

His playing partner, Australian Jason Day briefly headed McIlroy on the front nine when he went to ten under and McIlroy slipped back to 9 under.

But Day soon succumbed to the pressure and McIlroy kept his composure to extend his lead.

Behind him Tiger Woods among others threatened to close the gap but all faded before the final green.

McIlroy tees off tomorrow with Argentinian veteran Angel Cabrera from Argentian who is at 8 under.

"It’s a great position to be in,” McIlroy said after putting together a four-birdie, two-bogey round. “I stayed really, really patient out there today. I stuck to my game plan and it worked out. I feel my swing is in a great spot at the minute. I feel comfortable — with the way I played and finally feel comfortable on this golf course.”

Rory McIlroy on his way to winning the green jacketGuardian