Sydney Roosters have grabbed top spot on the NRLW ladder and ended North Queensland's finals hopes with a 24-12 win in Gosford.
It comes as Parramatta kept their mathematical chances of a finals berth alive by beating Canberra 18-16.
The Roosters joined Brisbane and Cronulla on 12 points but have the best for-and-against of the three sides. The minor premiership will not be decided until next week's final round of the regular season.
Newcastle are fourth on 10 points with a positive for-and-against of 74. The Cowboys are on eight points but their poor differential of -49 is too much to make up in one game, even though they host the Knights on Saturday.
There was plenty on the line for both sides and they played accordingly.
Roosters hooker Keeley Davis and back-rower Olivia Kernick have combined superbly this year and did so again for the opening try to the rampaging Kernick.
Cowboys captain Kirra Dibb has enjoyed a stand-out season and the skilful half stepped off her left foot to level it up at 6-6 in her old home town.
Dibb set up centre Jakiya Whitfield for her sixth try of the season and an upset was brewing.
Roosters forward Eliza Lopamaua was sin-binned for a hip-drop tackle but second-rower Amber Hall had a try awarded by The Bunker official Kasey Badger after it was ruled no-try on the field.
Roosters centre Jasmin Strange scored on the cusp of half-time to put a dagger in the hearts of the Cowboys.
It was the power game of the Roosters that proved the difference, with prop Otese Pule barging over for the decisive play.
Brydie Parker came into the side to replace injured playmaker Tarryn Aiken and impressed, with halves partner Jocelyn Kelleher one of the best on the park.
In Sunday's later game, Parramatta maintained their slim hope of a fairytale finals berth with an 18-16 defeat of Canberra at GIO Stadium.
To eke out a top-four finish from here, last season's wooden spooners must upset the ladder-leading Roosters next week and have Newcastle lose to the Cowboys.
The margins must combine to equal at least 85 points for Parramatta to leapfrog the Knights into fourth place.
Up 12-0 at half-time, the clumsy Eels invited eighth-placed Canberra back into the game through repetitive errors.
Parramatta's goal-line defence was stoic, notably denying Raiders behemoth Grace Kemp and scrambling to hold Mackenzie Wiki out.
But Raiders captain Simaima Taufa broke the levy and reduced the deficit to two points when she barged through the middle as the last 10 minutes approached.
Eels halfback Rach Pearson landed a crisp 40/30 kick to alleviate the pressure on Parramatta, putting centre Rory Owen in position to open up a six-point buffer as the minutes ticked down.
Pearson landed an ultimately crucial penalty goal soon afterwards.
Canberra winger Shakiah Tungai cruised over in the final minute but the Raiders made the mistake of not forgoing their conversion attempt.
Zehara Temara nailed the kick from the right-hand touch-line but there was not enough time for play to restart, as the Eels held on.