The Broncos beat the New Zealand Warriors 26-22 in Napier after the hosts were denied a potential match winning try due to a penalty in a tense finish.
With two minutes left on the clock the Warriors crossed for what should have been a game-tying try to Marcelo Montoya, only for it to be called back after review found Adam Pompey had held Deine Mariner back from making a tackle in the lead up, effectively ending any hope of a comeback.
With Reece Walsh, Selwyn Cobbo, Payne Haas, Thomas Flegler and Pat Carrigan all out ahead of Origin I, the return of Adam Reynolds from injury was always going to be important for the Broncos, and the veteran No.7 stood up big time in Napier.
His accurate boot was the difference in a game which saw both sides score four tries, with a perfect five from five giving Brisbane the edge on the scoreboard, while he made the break and provided the final pass for Ezra Mam's try on 53 minutes which broke the Warriors.
Also impressive was 20-year-old winger Mariner, who scored his first and second tries as an NRL player in what was his third game in first grade.
Despite giving up four tries, it was largely a victory built on defence for Kevin Walters' side, who denied the Warriors three certain tries in the first half with desperate goal-line efforts to hold players up or force errors.
After several near misses at both ends, it was Mariner who opened the scoring after he scooped up a loose ball and ran 80 metres for a memorable first NRL try.
After three blown chances earlier in the game, Dallin Watene-Zelezniak scored the first of his two tries on 36 minutes, only for Tom Ale to drop the ensuing restart which allowed the Broncos to score through Jordan Riki and take a 12-6 lead to the break.
A sharp run from Reynolds broke the Warriors' defensive line 13 minutes into the second half before he found Mam looming in support, and while the Warriors hit back a short time later, Brisbane replied again through Mariner.
Tries to Charnze Nicoll-Klokstad and Montoya set up a thriller, before Pompey's brain explosion denied the Warriors a chance at a possible famous victory.
The Broncos remain inside the NRL's top four, while the Warriors are still skirting around the edges of the top eight.