Having butchered a try 12 minutes from time, Ryan made amends with a stunning chip and chase as he hugged the sideline in the 77th minute to lock it up, Marshall's sideline conversion fading across the face of goal.
The game wasn't even two minutes old when Marshall had his first impact, with his grubber for the sideline bouncing cruelly for the Sharks and into the arms of Ryan for a dream start for the home side.
There was more than a hint of forward pass as the Sharks replied via Isaac De Gois, but Marshall answered like only he can as he danced his way over from short range.
The Tigers were revelling in rarely seen Sydney sun, but while they toyed at times with the Cronulla defence, they had no more points to show for their endeavours.
The mood darkened on the half hour when James Tedesco - with no-one near him - went down with a suspected season-ending ACL injury, halfback Tim Moltzen joining him in the sheds before the break with split webbing which required stitches.
Marshall produced a pearler of a cut-out pass to put Matt Utai over nine minutes after the restart, but the powerful winger couldn't keep his heel in the field of play with the Tigers denied by the video referee.
Carney then awoke from his slumber.
He delivered a cut-out pass to Colin Best who juggled before diving over, then the 2010 Dally M medal winner did it all himself with two big right foot steps to give the Sharks their first lead at 14-12 with just over 20 minutes remaining.
Best couldn't help himself as he was pinged for a double movement as he chased his double, the desperation and heat affecting players from both sides.
Marshall almost conjured up another magic trick with a deft grubber at the Sharks line which was fumbled by Nathan Gardner, but Ryan couldn't finish off the job as he fumbled the ball over the line.
But he more than made up for it with his late solo effort.
WESTS TIGERS 17 (B Ryan 2 B Marshall tries B Marshall 2 goals B Marshall field goal) bt CRONULLA 16 (C Best T Carney I De Gois tries T Carney 2 goals) in golden-point extra time at Leichhardt Oval. Referee: Jared Maxwell, Chris James. Crowd: 19,762.