Canterbury have suffered a body blow just a week out from the NRL finals, going down to South Sydney 28-10 in a fiery affair at ANZ Stadium.
Des Hasler's men could sink as low as seventh after suffering their third straight loss in a worrying sign heading into next week's elimination final against Penrith.
Besides a brief period in the opening half, South Sydney - who finished an otherwise disappointing year with four wins on the trot - always looked in control.
After the Rabbitohs took a 12-6 halftime lead, tempers threatened to boil over with Dogs captain James Graham and Souths forward Sam Burgess involved in a heated confrontation.
Graham took offence to a "prowler tackle" and struck out with his boot at his fellow northern Englishman.