Brisbane continued the pattern of upsetting the rhythm of top-four teams with a courageous 22-8 win at Allianz Stadium on Saturday night after losing hooker and chief organiser Andrew McCullough in a head clash with Roosters hardman Dylan Napa.
Earlier in the day 10th placed Canberra rolled South Sydney, while the 12th placed Titans gave competition leaders Storm a real shake-up losing a tight one 10-8 at Cbus Stadium.
The Broncos bucked the trend with their 14 point win saw them push the Warriors back into eighth spot on differential.
But the match was held up for several minutes with virtual silence around the stands when McCullough was injured.
The sight of the 28-year-old convulsing on the ground after Napa had hit him flush on the jaw with his head was not a pretty one.
It conjured up memories of Napa hitting Broncos forward Korbin Sims with his head and breaking the Brisbane forward's jaw at Suncorp Stadium in round 11.
Dylan Napa on report
But early medical reports from the Broncos staff said McCullough had a gash to his face but there were no signs of any fracture. He will probably be sent for scans anyway.
Napa's 24th minute tackle was placed on report by referee Gerard Sutton and he sat in the sin-bin for 10 minutes. He looked visibly upset as his Queensland Origin teammate was taken from the ground on a medi-cab.
But if the Broncos were expected to fall into a heap, think again.
The Roosters threw everything at them in the second half trying to find holes in their defence and points for their scoreboard. James Tedesco and Joseph Manu crossings were over-ruled for a knock-on and a foot into touch respectively, which would have helped substantially.
But in the end the courage of the Broncos handed Roosters back-to-back losses for the first time in the 2018 Telstra Premiership season, after losing to the Raiders last weekend.
It also stopped the Roosters run of dominance – five straight wins - at their home ground over the Broncos.
The Roosters welcomed back five-eighth Luke Keary for the first time since the round 20 win over the Dragons after a knee injury. He set-up the Roosters only try with deft kick to the right corner for Blake Ferguson in the 12th minute.
The lead changed three times inside the opening 16 minutes as the sides traded tries and goals. A Latrell Mitchel penalty in the 20th minute locked things up at 8-8. It also gave Mitchell his 200th point of the season.
But then the Napa-McCullough incident happened and despite the Broncos being the ones who lost a vital cog in their wheel, it was the Roosters who seemed to lose the plot.
The Broncos scored two tries and two goals to shoot to a 20-8 lead at halftime.
Match: Roosters v Broncos
Round 24 -
Venue: Allianz Stadium
One of those tries to halfback Kodi Nikorima came of a comical Roosters mistake, when fullback James Tedesco and winger Daniel Tupou got in each other's way trying to retrieve an Anthony Milford bomb.
Nikorima was the man on the spot to collect the ball and race 10 metres to score.
It had all the hallmarks of Tedesco and Blake Ferguson colliding in another embarrassing mix-up in the round 20 win over the Dragons as they chased a Ben Hunt kick.
News & Notes: Broncos interchange forward Patrick Mago had an HIA test in the 46th minute and passed ... Latrell Mitchell sin-binned in the 56th minute... Roosters winger Blake Ferguson sits on 99 career tries... the Roosters play the Eels next Saturday at ANZ Stadium to finish off the regular season, while Brisbane is at home for the Sea Eagles on Sunday ... Crowd: 13,263.