Reigning Super League title-holders Hull KR, once on the brink of going out of business before winning a domestic treble last season, led by 26 points early in the second half.
Mikey Lewis's kicking game led to a succession of Broncos' errors, with tries from Tom Amone, Elliot Minchella and Joe Burgess leaving Hull KR 18-4 ahead at half-time in front of their own fans.
Gehamat Shibasaki scored the Broncos' lone try before the break against a Hull KR side transformed after starting their Super League title defence with a shock loss to promoted York City Knights last week.
Any thoughts of a fightback by Brisbane, playing their first match since beating Melbourne Storm in the NRL Grand Final in October, appeared fanciful as Hull KR's Oliver Gildart and Peta Hiku added further tries in the second half to extend the hosts' lead to 30-4.
Yet the Broncos, who came from behind three times in last year's NRL final series, hit back with four tries in 16 minutes through Patrick Carrigan, Deine Mariner, Shibasaki again and Kotoni Staggs to the despair of Robins supporters at the MKM Stadium in Hull.
But an increasingly exhausted Hull KR side clung on as they became the first club since Wigan in 2024 to hold the four major titles an English club can win at once.
Australia completed a 3-0 Ashes series clean sweep of England in November, reinforcing concerns about a gap in standards between two of the 13-a-side code's leading nations.
But Hull KR coach Willie Peters told the BBC: "I'm proud of everyone involved in our club. I'm happy for our owner Neil Hudgell and the people of Hull.
"We had a responsibility for more than our local community, it was for Super League and the British game and we did them proud."
Brisbane Broncos boss Michael Maguire had no complaints about the outcome.
"They came out quick and fast and we made some errors in the first part of the game and put pressure on ourselves," he said.
"We conceded some soft tries but you've got to respect everything in the game. It's a good wake-up call and a realisation of what this game demands."
