A Scott McDonald double against Kilmarnock at Rugby Park took Celtic three points clear at the top of the Clydesdale Bank Premier League and on course for their fourth title in a row.
The champions dominated the first half but Danny Invincibile's volley after 36 minutes cancelled out his fellow Australian's opener 10 minutes earlier.
Celtic huffed and puffed at times after the break but with 10 minutes remaining McDonald struck with a wonderful solo goal to ease the Parkhead side ahead of Rangers who sensationally lost to Inverness at Ibrox.
McDonald came close to scoring in the third minute, but the Australian found the target to put the champions ahead on 26 minutes. He had yards of room inside the Killie box when Crosas picked him out with a quick pass and although Clancy came to challenge, he was turned easily before the ball was driven past Combe and in to the far corner of the net.
Celtic keeper Artur Boruc had to push a Hamill cross-cum-shot over the crossbar but in the 36th minute, from a more fruitful corner, Invincibile equalised.
Craig Bryson's corner from the left somehow made its way through a ruck of players to the Australian at the back post who beat the Poland international with a right-footed volley.
Ben Hutchinson replaced the ineffective Samaras as the visitors drove forward for the next goal but it was McDonald who grabbed it 10 minutes from the end. The Australian picked the ball up from McGeady at the edge of the Killie box, turned David Lilley then sent a clutch of Rugby Park defenders the wrong way with a sway of the hips before toe-poking the ball past Combe.