Fullback AJ Brimson starred for the Titans, who fought back from 12-0 down after eight minutes and hoisted themselves temporarily from the bottom of the NRL ladder in Auckland today.
Arguably the most significant acquisition in club history, Hasler entered round eight on the equal third-longest losing streak of any NRL-era coach, a 13-game slide that stretched back to the end of his tenure at Manly.
But there had been a sense that a win was brewing for Hasler and the Titans, who withstood a late Warriors onslaught to secure their drought-breaking win at Mt Smart Stadium.
Preliminary finalists last season, the Warriors are now winless in their past three games, and for a second week running they let their guard down after dominating their opponents early on.
The Warriors stormed back into the game late and had 22 play-the-balls inside the Titans' red zone in the final 20 minutes.
But they could not find the killer blow, haunted by poor fifth-tackle options at close range.
Brimson, deployed at centre, five-eighth and fullback through eight rounds, mounted a case to remain the Titans' No 1 even after Jayden Campbell returns to fitness.
The first of Brimson's two tries began the Titans' comeback, the plucky utility supporting Alofiana Khan-Pereria down the left side to get his side up and about.
His second four-pointer came from an offload by super-sub David Fifita, whose own try had given the Titans their first lead of the day in the final minutes of the first half.
Brimson was equally valuable in defence amid the Warriors' late flood of possession, first holding up Dallin Watene-Zelezniak, then grounding the ball in the in-goal to stop another certain try in the final four minutes.
Beleaguered playmaker Tanah Boyd looked the most confident he has this season, dummying to fool Jacob Laban and crash over for Gold Coast's second try. He kicked a field goal to make it a two-score game against the odds at halftime.
The Warriors had appeared set to put a cricket score on the Titans when they crossed twice inside six minutes, Charnze Nicoll-Klokstad and Addin Fonua-Blake each scything through some brittle Gold Coast defence.
But ill discipline cost the Warriors and invited the Titans to storm back into the game down their lethal left edge.
Fifita went on report for collecting the legs of kicker Te Maire Martin in the second half, with Brian Kelly also in hot water for hitting Watene-Zelezniak high.
In-form Warriors hooker Wayde Egan went on report for a high shot on Brimson in the first half, but appears unlikely to miss any time.
