Issac Luke

Issac Luke ... put in an impressive performance against the Raiders on Saturday night. Photo: Quentin Jones

SOUTH SYDNEY have won just one game when Issac Luke has come off the bench this season.

Rabbitohs coach Michael Maguire has experimented with the tactic of using Luke as an impact player four times this year, and while nearly everything he's done has turned to gold in his debut season, that particular ploy didn't.

The difference in performance between the Rabbitohs' first finals loss to Melbourne, when Luke came off the bench, and Saturday night's win against the Raiders summed up how important the 25-year-old is to their title hopes.

Nathan Peats hasn't let anybody down when wearing the No.9 jersey, but if the Rabbitohs learnt anything from their win against Canberra, it's that Luke needs to start.

So destructive was Luke, Maguire opted to leave him on the field for 70 minutes before replacing him with Peats in the final minutes.

The Kiwi international tore the Raiders apart in a dynamic opening to the match, which five-eighth John Sutton believes was the foundation to his side's victory.

''Last week we started very poorly against Melbourne and it got to 18-0 before we even knew it,'' Sutton said. ''This week we wanted to start strong, and I thought Issac Luke out of dummy half was brilliant. Especially in those opening parts, he just tore them apart and got us on the front foot. He adds a lot to this team.''

Luke ran 14 times for 142 metres on Saturday night, the 16th time in 21 games this year he's cracked the century for metres gained.