Paul Vaughan swamped by Rabbitohs defence.

First-half defence inspired Rabbitohs' win: Seibold

Proud South Sydney coach Anthony Seibold says despite the focus on his side's improved attack, it was a period of sustained goal-line defence in the first half that gave them the confidence to go on with a win against ladder leaders the Dragons.

Billed as a clash between two of the competition's in-form sides, it was the now-fifth-placed Rabbitohs who looked the more potent throughout the upset 24-10 win.

After bursting out of the blocks with two quick tries, however, they had to soak up plenty of pressure with the Dragons enjoying six attacking sets in short succession midway through the opening stanza.

But the Bunnies repelled them every time and eventually went down the other end to stretch their 10-0 lead to 12 via a penalty goal.

"There's been a lot of talk about our attack and the improvement in that part of the game so far, but I thought it was our 'D' that won us the game today," Seibold said after the game.

"The Dragons are the number one side for a reason and made it really tough for us to score points and they're a really good attacking side so I was quite pleased with the 'D' today.

"The guys defended really well in the first half in particular." 

He said the team got particular confidence out of that stretch of goal-line defence.

"One thing I've seen with the Dragons, any time they get good field position they normally go away with some points," he added.

The match also saw in-form Bunnies rake Damien Cook slightly out-point Dragons rival Cam McInnes in what had been billed as a possible play-off for a NSW jersey for the Holden State of Origin opener.

Cook was again strong, running for 79 metres and making three busts to go with a typically busy 43 tackles, while also helping create the final-minute try to Campbell Graham. McInnes was one of his team's best as well, making a match-high 48 tackles with just one miss while running 70 metres with two busts and two offloads.

Quizzed about his teammate's hopes of an Origin debut, Maroons legend and Bunnies skipper Greg Inglis was confident Cook could handle it but was reluctant to get drawn into too much Origin talk.

"Cooky, you guys have seen what he does in 80 minutes, Cooky has been working his backside off going in [to the coaching staff] and wanting to learn," Inglis said.

"That's the character and person he is. We see what he does on the training field and what he wants to concentrate on is doing the best he can for South Sydney and the team. It's a credit to him.

"Around the corner, if he gets picked, all the best to him. As far as Cooky is concerned he just wants to put his hand up and play his best footy for us first.

"No doubt [he could do a job] but you have a chat to Cooky, he wants to turn up each and every week for Souths."