If the Sharks are to claim their first ever NRLW premiership they'll have to do it the hard way against the highly fancied Roosters but that's just how star centre Annessa Biddle likes it.

Few gave Cronulla a chance against Brisbane last week and few would have given Biddle a shot at outpointing Broncos star Mele Hufanga, but the Otara Scorpions product dominated her more fancied opposition as the Sharks pulled off a 14-0 upset.

Hufanga is one of the most destructive players in women's rugby league, a hurricane of speed and power who has left many a defender grasping at air or broken on the ground behind her.

Biddle admits she didn't have much of a plan — the young centre just threw her shoulders into Hufanga and didn't worry about what happened next.

Even now, she's not quite sure how it happened, she just knows she craves the challenge of taking on the best attacking players the game has to offer, and the better they are the better for her.

"I'm so glad our team had faith in me to mark Mele. I have no idea where that aggression came from, I was like where has this been in the rest of the games?" said Biddle.

"But something just hit me on game day, that we had to make it to the grand final and I had to play like it was my last ever game.

"I'm such an aggressive player and I love a bit of contact, even if I get hit that's fine. Every time I go in for a tackle I have to make sure I'm in it 100 per cent.

"I love how aggressive this game is. I love the competition, especially with someone like Mele who has footwork and size, it was awesome."

Biddle blew right past Hufanga for a try and kept her wrapped up in defence in a coming of age performance, but she'll have to repeat the dose against Tricolours legend Isabelle Kelly if the Sharks are to pull a fast one on Sunday.

By outpointing Hufanga, it feels like there's nothing the 21-year-old can't do and there's no prizes for guessing how she's going to go about it.

"I'll do a lot of study, try and shut her down early once I know what she does, stop her from getting that time and space," Biddle said.

"We have so much adrenaline and it's nerve-wracking but also exciting. It's our first time for the whole club and it still feels a bit unreal."

Cronulla shook off three straight losses to stun Brisbane in the semifinal, a revival Biddle puts down to the inspirational leadership of fellow centre and captain Tiana Penitani, who's acted as a mentor since Biddle joined the club last season.

"It's the little things – maintain your mental space, learning to deal with high pressure moments," Penitani said.

"I haven't had to teach her much, but when she came to us for pre-season last year she was pretty green.

"But she's worked really hard, learned the ins and outs of the game and fine-tuned her skills.

"Her quick pass, her flick passes to Georgia (Ravics), her defensive reads and understanding the system, she's such a talent, I don't want to take any credit because she's done so much herself."

Penitani is coming off a fine season in her own right after being named in the team of the year at the Dally M's earlier in the week.