The Baby Broncos overcame the loss of rookie halfback Sean O'Sullivan to become the third team in as many weeks to make Cronulla pay for poor goal kicking, stunning the Sharks 24-22 at Pointsbet Stadium.
The obvious solution to Cronulla's woes may also not be an option in coming games after Kyle Flanagan – who kicked the club's first successful conversion after seven straight misses – was placed on report for kneeing.
The Sharks scored five tries to four but as in their previous two losses to Canberra and Canterbury goal kicking costs them dearly and they are now in danger of sliding out of the top eight unless they beat Melbourne in Cameron Smith's 400th game next Saturday night.
“I haven’t seen anything like it to be honest, three games in a row where we haven’t been able to kick a goal and it has cost us on the competition ladder," Cronulla coach John Morris said.
"I think if we had kicked a couple of goals in those last two games we could have been playing off for second spot today. Instead we have slid the other way, but there are certainly other parts of our game that are putting us under pressure."
The injection of Flanagan midway through the second half appeared to ease the problem after he converted winger Josh Morris's third try but the talented playmaker faces a possible suspension after being placed on report for kneeing Broncos prop Matt Lodge in the head.
Lodge may also be in trouble after lashing out with his leg and tripping Flanagan in retaliation but the incident coincided with Cronulla losing their way as they led 22-12 at the time.
Match: Sharks v Broncos
Round 16 -
Venue: PointsBet Stadium, Sydney
- Nine Network
- LIVE PASS
Brisbane's win was even more impressive as the inexperienced Broncos lost O'Sullivan at halftime with a hamstring injury and centre Gehamat Shibasaki in the second term with a compound dislocation his finger.
Hooker Andrew McCullough moved to the halves to partner Jake Turpin, who scored the winning try in the 75th minute.
Cronulla captain Paul Gallen (glute) and fullback Matt Moylan (hamstring) also failed to finish the match.
Besides captain Darius Boyd, who was making his 305th Telstra Premiership appearance, the combined NRL experience of the Brisbane backline totalled 41 matches, with centre Kotoni Staggs (22) being the only one to have yet reached double figures.
"The Sharks had 1,000 more NRL games than us tonight, so I was really proud of the guys," Brisbane coach Anthony Seibold said. "We had 10 guys with less than 13 games and four of those guys were making their debut."
Yet it took teen wing sensation Xavier Coates just nine minutes to confirm that he has a long NRL career ahead of him after leaping above Morris to catch a kick by Turpin and score on debut.
Coates, who was man of the match for Queensland in last month's under-18s State of Origin, has a habit of scoring tries and he got a brace in his only Intrust Super Cup match for Tweed Seagulls and the club's under-18s National Championship final against Illawarra Steelers.
Former Test star Josh Dugan hit back for Cronulla in the 13th minute when he beat 19-year-old former Manchester United scholarship holder Herbie Farnworth, who was making his NRL debut on the wing, and stepped inside Staggs to score.
Dugan had earlier lain prone in the in-goal after being sandwiched between Boyd and Staggs while chasing a Shaun Johnson kick and he flinched when a Sharks physio touched his lower back.
However, he recovered to score and his pain would have eased further when halfback Chad Townsend grabbed Cronulla's second try in the 19th minute after grubbering into the in-goal and pouncing on a fumble by Coates.
The Sharks had a reprieve when Coates was disallowed a try after again leaping above Morris for a Turpin kick only for the Bunker to rule he had knocked the ball forward into his opponent before regathering but it was only a matter of time before the Broncos scored again.
Tongan forward Tevita Pangai jnr regained the lead for Brisbane when he dived on a loose ball in the Cronulla in-goal to score in the 32nd minute after a communication mix-up by Townsend and Moylan forced Morris to race in and try to clear the ball.
Trailing 12-8 at halftime, Morris would have again been concerned by his side's failure to land a goal, as well as Johnson's inability to get to a kick on the last tackle on one occasion and a loose carry by Moylan as he returned a kick from his own line.
The goal kicking woes continued after halftime as Townsend missed his conversion attempts of Morris's first two tries in the 46th and 52nd minutes – the latter following a midfield break by Jack Williams, who linked with hooker Jayden Brailey and Moylan.
After replacing Brailey at dummy-half, Flanagan landed Cronulla's first goal in three weeks when he converted Morris's third try in the 56th minute but ill-discipline from the rookie playmaker eased the pressure on the Broncos after he was penalised for kneeing Lodge.
The incident occurred as Lodge was trying to play the ball on his own line and the Brisbane prop lashed out with his right leg to trip Flanagan after getting to his feet.
To make matters worse for Flanagan, fellow Brisbane prop Payne Haas ran over him to score at the other end in the 60th minute and reduce Cronulla's lead to 22-18.
Turpin then added further insult when Pangai put him over to score five minutes from fulltime and Johnson was replaced by Brailey with the game being on the line, and he watched as the Broncos hung on to win.
“That one really hurts," Morris said. "The boys are really in an ordinary way at the moment. I feel for them but we need to be accountable.
"That was a pretty ordinary second half. That’s the third week in a row where we have scored more tries than our opposition so we shouldn’t be getting beat. The damage is done."