Jaydn Su’A was binned for the second week in a row and it cost the Dragons dearly.
Su’A was controversially given his marching order for a late hit on Panthers halfback Sean O’Sullivan last week.
This time it was a high shot on Sharks star recruit Dale Finucane and Su’a was put on report for the 16th minute incident.
But not everyone was convinced he deserved the sanction which which proved a game-changing moment.
Sharks centre Jesse Ramien was binned in the 73rd minute for a high shot on Dragons forward Jack Gosiewski - but the score was already 36-6.
Gosiewski scored a consolation try before Andrew Fifita was binned in the final 90 seconds for tackling Francis Molo without the ball.
The Sharks finished the game with 11 men on the field, but it didn’t matter as the damage had already been done.
Cronulla quickly made the Dragons pay for Su’A’s sin bin as Sione Katoa crossed in the 18th minute and then Matt Ikuvalu went over moments later.
Siosifa Talakai made it three tries in 35 minutes when he caught a high ball and crashed over to score.
The Dragons put a disastrous first half behind them to strike first in the second stanza and make it 18-6 after 42 minutes.
Sharks centre Jesse Ramien finished a sensational team try in the 48th minute but replays appeared to show Andrew Fifita marginally off-side.
Cronulla prop Braden Hamlin-Uele crossed next and then halfback Nicho Hynes got in on the act for the Sharks’ final try.