A masterclass from centre Indie Bostock has allowed the Illawarra Steelers to remain undefeated and clinch the Tarsha Gale Cup title over rivals Newcastle Knights, defeating them 24-12.

In an entertaining match-up, Player of the Match Bostock has shattered the dreams of her opponents as they aimed to emerge victorious and claim their first Grand Final victory in four appearances.

"We worked so hard through the pre-season to get here and words can't describe how keen this is. It's so good," Bostock told Zero Tackle after a magnificent outing in the Steelers jersey.

"We've been working as a squad all together for the past two years to get this, so definitely been dreaming about it.

"It's a reward for knowing that my hard work's paying off like training and it just feels good that it's showing on the field.

"My brother and my dad (have been so important to my journey). They're my biggest fans, so knowing that they're here to support me means a lot to me. They're my everything."

The best team throughout the entire season, the Steelers entered the match having previously won eight games in a row with a points difference of 316.

However, it was their opponents who were given the first opportunity of the match.

The Knights were provided with an added advantage to begin the game after winger Lilly McNamara scored in the opening minute of the match, following an unforced error of the kick-off.

Down by four points, centre Indie Bostock took control of the match, providing quickness from the play-the-ball, eloquent passing, athletic footwork and pure speed with her bright blue boots.

Indie, sister of Dolphins rookie Jack Bostock and nicknamed 'Ferrari,' bagged a quick double after Maria Paseka crossed the line to give the Steelers the lead.

Renowned for her try-scoring ability, her first try came from a glorious regather from a cross-field kick, while her second saw her run the length of the field.

The Knights would score two of their own, but failed conversions saw them remain behind for the majority of the match.

Despite multiple opportunities in their opponents' 20 metres, they struggled to get anything going in attack and looked lacklustre and clustered with the ball in their hands.

With the game up for grabs, the Steelers defended effortlessly before the halves' combination of Evie McGrath and skipper Kasey Reh took control in attack. Before Bronte Wilson delivered the final nail in the coffin to the Knights.

Illawarra Steelers 24 (Tries: Indie Bostock 2, Maria Paskea, Bronte Wilson Goals: Chelsea Savill 3 Ella Koster) def Newcastle Knights 12 (Tries: Lilly McNamara, Aylah McCulloch, Malaki Poa)