Cronulla's late-season slump has continued with a 12-6 loss to a Cody Walker-inspired South Sydney in Sydney.
Walker starred for the Rabbitohs alongside Sam Burgess and Nathan Brown as they handed the Sharks their third successive loss, and made their winning streak of 15 a distant memory.
Missing captain Paul Gallen to a calf injury, the Sharks looked sluggish for much of the contest on a cold and wet night.
In the absence of Adam Reynolds, who left the field with a concussion in the 26th minute, Walker led the Rabbitohs with aplomb and scored one of their two tries.
An 80th-minute try by Joe Burgess sealed the Rabbitohs' seventh win of the season, with the winger and Brown leading the way for the home side up front.
James Maloney and Wade Graham tried hard to spark the Sharks in the second half, but the visitors lacked execution and composure as they pressed for a come-from-behind win.
The duo combined for Cronulla's only try in the 53rd minute.
Souths five-eighth Walker scored the only try of the first half when he dashed under the posts from close range in the 33rd minute.
A Damien Cook penalty after the half-time siren gave Souths an 8-0 lead at the break.
Cronulla sit in second place after 24 rounds, a point above third-placed Canberra and need to win their final games against Sydney Roosters and Melbourne to confirm a top-two finish.
Maloney could be in judiciary trouble for two high tackles late in the game.
The Sharks' winning streak ended in July with a draw against Gold Coast.