The young Brisbane side learned a heartbreaking lesson to give up the biggest lead in a grand final in premiership history to lose against Penrith.
The genius of Panthers maestro Nathan Cleary aside, the Broncos needed to be almost perfect to win.
They were far from it in the 26-24 loss after leading 24-8 with 24 minutes remaining.
Errors came back to haunt them despite the electrifying speed, razzle dazzle and resilience they displayed in abundance.
Fabulous five-eighth Ezra Mam's second half hat-trick replicated Brisbane centre Steve Renouf's achievement in the 1997 grand final but remarkably it turned out to be not enough.
Mam stamped himself as a generational player.
The Panthers completed 10 from 10 sets to start the match. The Broncos completed four from 10.
They imploded when leading by 16. Errors late in the game cruelled them again.
Centre Herbie Farnworth dropped the ball early. Half Adam Reynolds fumbled a Payne Haas offload. Winger Selwyn Cobbo spilled his lollies. Centre Kotoni Staggs made a mistake in the play the ball.
Farnworth batted a short dropout straight to Panthers hooker Mitch Kenny who scored. Reynolds kicked out on the full from another short restart and Nathan Cleary landed the penalty.
Broncos fullback Reece Walsh was limping early in the match and was not able to influence the game, mainly because the Broncos kept coughing up the ball.
The 21-year-old knocked on and was dragged into his in-goal after running sideways. He also kicked the ball dead. It wasn't his night in the first half where he made 32m from six runs. He gave the Panthers a seven tackle set early in the second half before showcasing some of his best.
Captain Adam Reynolds injured his groin in the 25th minute and looked gone for all money. He soldiered on bravely and was heavily involved in the 39th minute try to barnstorming prop Thomas Flegler, who had earlier passed an HIA.
The Broncos had no right to be trailing by just two points at the break. Farnworth made two rip-roaring try savers on opposite number Izack Tago and one on fullback Dylan Edwards. The England international was just as imposing in attack.
Second-rower Jordan Riki also saved two try-scoring possibilities with desperation.
Winger Jesse Arthars had his best game in a Broncos jersey.
Just two of the Broncos - Reynolds and Kurt Capewell - had played in grand finals compared to 13 of the Panthers.
Coach Kevin Walters has done an extraordinary job to take the side from wooden spooners in 2020 to make a grand final just three years later.
