The Australian international gave the champions the lead after seven minutes, when he nodded in from close range after Jan Vennegoor of Hesselink's header was blocked, and added a double in the second half after the Parkhead men had survived some nervy moments.

Gordon Strachan's men sit at the top of the table on goal difference as they look forward to Wednesday's Champions League clash with AC Milan at Celtic Park.

The match ended in a comfortable win but there was little indication in the first half that the three points would be attained so easily.

Earlier in the day Rangers could only manager a 1-1 draw away to a spirited Motherwell. The home side took the lead in the 23rd minute when Chris Porter collected David Clarkson's superb pass to fire home his fifth goal of the season, but Kris Boyd levelled from the spot after DaMarcus Beasley was felled.