Nicho Hynes's golden-point field goal has strengthened Cronulla's bid to claim a spot in the top four as the Sharks held off a 12-man South Sydney to claim a 21-20 NRL thriller.
Rabbitohs prop Tom Burgess was sent off in the second half of extra-time for a high shot on Ronaldo Mulitalo and is likely to face suspension.
After referee Gerard Sutton dismissed the English forward, who became the second player after Penrith's Nathan Cleary to be sent off in round 20, Hynes took control of proceedings.
Cronulla took three hit-ups and Hynes was back in the pocket to coolly nudge the ball between the sticks to send the 11,492 fans at Shark Park berserk.
His successful field goal came after Cronulla five-eighth Matt Moylan failed with two attempts and South Sydney's Latrell Mitchell made a hash of three shots.
"He (Hynes) is a really good decision maker," said Sharks coach Craig Fitzgibbon.
"I had looked at a lot of his football when he was playing in the halves (before he signed with the club) and it's been a good move.
"We got it done in the end and it was a wild old night and to hang in there and I was proud to get away with a win."
South Sydney coach Jason Demetriou didn't want to discuss Burgess' shot on Mulitalo but said that Mitchell was stinging after missing three golden chances to extend the Rabbitohs' four-game winning run.
"Tommy was coming across and trying to make a tackle, I can't really comment because I didn't see the replay either," Demetriou said.
"Latrell's dirty, that's a moment he nails a lot of the time but it's not on him. There's 80 minutes of footy that went before we got to that point."
Demetriou may also come to regret the decision to move Mitchell to the centres after Jed Cartwright went down with a hamstring injury and he opted to shuffle Kodi Nikorima into fullback.
The loss is also costly for Souths' hopes of a top-four spot given they face the Warriors, Parramatta, Penrith, North Queensland and the Sydney Roosters over the remaining five rounds.
The victory makes Cronulla's record at Shark Park 7-1 and they are only in third spot because of second-placed North Queensland's superior points differential.
With a comfortable run before the finals Fitzgibbon's men will be confident they can finish second and secure a home semi-final after seeing off Melbourne, the Cowboys and Souths over July.
It wasn't straightforward on Saturday with a Mitchell penalty and an Alex Johnston try giving Souths an early advantage.
Connor Tracey and Mulitalo responded for the Sharks, with Hynes adding a penalty to give Cronulla a 14-8 half-time lead.
Mitchell scored not long after half-time with neither side relenting for a good 20 minutes.
Cronulla got the breakthrough as Andrew Fifita rolled back the years with a cavalier run to give the home side a 20-14 lead with less than a quarter of an hour to go.
Fifita's carries were critical given the Sharks lost Royce Hunt to a suspected shoulder injury.
Tevita Tatola barged over for Souths and Mitchell added an easy conversion late on to send the game to golden point.
Mitchell and Moylan both fluffed their attempts but after Burgess was sent Hynes was 20m and from right in front to seal a valuable victory.
