Johnathan Thurston has once again orchestrated a miraculous win for the Cowboys, ending Brisbane’s season in another extra-time Queensland derby.

In just the latest chapter in the great rivalry between these two teams, Thurston brushed off representative back rower Sam Thaiday and produced a superb flick pass for Michael Morgan to score in the first half of the new finals extra-time period, securing a heart-stopping 26-20 victory and sending the Broncos packing in heartbreaking circumstances for the second-straight year.

The Cowboys trailed 20-18 in the penultimate minute of regulation when Thurston stepped inside Broncos back rower Matt Gillett, who stuck his leg out, eliciting a penalty for a trip.

The battle of the forwards was ferocious. Photo: ABC

Despite exhaustion setting in for everyone, North Queensland’s skipper stepped to the plate and did what he has done so many times before.

He potted the clutch goal to level the scores, and landed the killer blow in the first five-minute period of added time – a new alternative to golden point introduced for this year’s finals series.

The six-point win was as thrilling as any game played in the history of the derby, but was actually the biggest winning margin of their past five clashes – edging last year’s qualifying final, won 16-12 by Brisbane, which was followed by three successive one-point games.

The Cowboys now move into a preliminary final against Cronulla in Sydney as they attempt to win back-to-back premierships, but they will have their work cut out for them as they meet a fresh batch of Sharks after one of the most exhausting games of the year.

Brisbane started the game about as badly as possible, with Andrew McCullough booting the ball out on the full while trying for a 40/20, but he made up for it minutes later when Matt Scott rolled away from a tackle injured and the hooker scooted over to score from close range.

Jordan Kahu’s conversion made it 6-0 and, clearly anticipating another close game, the Broncos had no hesitation pointing to the posts when they were awarded a penalty in the 12th minute.

The Cowboys must now face the hungry Sharks. Photo: Getty

While the Broncos were dominating with their forwards — Adam Blair in particular having a whale of a game — the Cowboys turned to their zippy outside men to make an impact.

First they found schoolboy sensation Kalyn Ponga, an 18-year-old under-20s star making his debut in place of the injured Antonio Winterstein, flying down the wing and beating Darius Boyd and Ben Hunt with a pair of left-foot steps, coming within a whisker of a long-range try only to be called back for an obstruction.

But the other side of the field yielded better results shortly after as, seemingly out of nowhere, winger Kyle Feldt brushed off centre Tom Opacic and flew downfield before finding Justin O’Neill, who unloaded to rookie back rower Coen Hess to dive over on the right wing for an 88-metre team effort.

Trailing by four points, the Cowboys inexplicably took two points when awarded a penalty right in front in the 33rd minute and felt the impact on the stroke of half-time, when Lachlan Coote fumbled a Boyd grubber and Kahu touched down, allowing the visitors to take a 14-6 lead into the break.

Despite having the best of the possession, the premiers failed to break through in the second half until two bits of brilliance from veteran centre Justin O’Neill; first freezing rookie Opacic with a right-foot step to score in the 57th minute before burning Glenn, replacing Opacic in the centres, with pure speed to score five minutes later.

The Cowboys were surging and looked to have one foot in the preliminary finals when Thurston grubbered close to the line in the 69th minute only for Anthony Milford to clean up.

A blistering run by Glenn followed, flipping momentum and allowing Boyd to get on the front foot from dummy half, sending away Corey Oates, who had had a bad night up to that point, for a 70-metre effort.

Kahu’s conversion looked to be enough until the dying stages, when Thurston landed his game-tying penalty goal.

On the Cowboys’ first trip into Brisbane’s red zone, Jason Taumalolo made a trademark bullocking run, putting the Broncos on the back foot and Thurston took advantage.

He went to the line, fending off Thaiday and flicking back to running mate Morgan for the game-winner.

Making matters worse, Boyd dropped the kick-off after the change of ends and the referees controversially ruled it a knock-on.

The Broncos had a few other chances, but errors created by fatigue made any more points unlikely and ultimately unattainable.