Benji Marshall's bold captain's challenge sets Tigers on their way to NRL win over Sharks

Sydney: Cronulla's nightmare week has continued after bombing a second-half lead to fall 2816 to Wests Tigers at Bankwest Stadium on Saturday.

The league was rocked this week when Sharks youngster Bronson Xerri was provisionally stood down for testing positive to performance-enhancing drugs.

But their campaign took a dark turn after being held scoreless in the second 40 to leave them without a win from their opening three games.

Compounding the pain for coach John Morris is a suspected hamstring injury to halfback Chad Townsend.

Cronulla appeared on their way to overcoming a dramatic week when they surged to a 1610 halftime lead off the back of two Josh Dugan tries.

A Luke Garner try and Benji Marshall penalty goal levelled the scores with 20 minutes to go, before the Sharks fell behind on a horror defensive play.