The Rabbitohs produced a stunning second-half surge to beat arch-rivals the Roosters 28-16 at Accor Stadium on Friday night.
With rookie halfback Lachlan Ilias finding his feet and gun No.1 Latrell Mitchell digging deep into his bag of tricks the Rabbitohs turned a 12-6 half-time lead into a comprehensive win.
With so much at stake, the Rabbitohs charged out of the blocks with skipper Cameron Murray setting the tone with a try in the ninth minute.
The Roosters then invited their arch-rivals to double the lead with an error from a tap restart and Alex Johnston obliged with the 138th try of his career.
Roosters centre Joey Manu had raced up and taken a quick tap and passed to James Tedesco who tried to find Billy Smith but the ball went astray, Murray scooped it up and found Johnston for an easy stroll to the corner.
Some brilliant lead-up work by Manu set Tedesco up for a try in the 25th minute and the Roosters were back in at 12-6.
That's how it stayed until the break but the second half was barely a minute old when the Roosters got back to 12-10 through a sweet stepping try to Manu after the Rabbitoh George Burgess had coughed up possession in the opening set.
With rookie halfback Lachlan Ilias growing in confidence the Rabbitohs hit back four minutes later when Cody Walker crossed for his first try of the year after good lead-up from the No.7 and Murray.
Latrell Mitchell looked to have answered Manu's try soon after when he regathered a Johnston grubber and planted the ball down but replays showed the winger had dropped the ball before it made contact with his foot.
With 20 minutes remaining the Rabbitohs had a second try disallowed when Keaon Koloamatangi was ruled to have lost the ball and failed to regrip it before grounding after storming over from dummy half.
Not to be denied, Koloamatangi took a pass from Damien Cook close to the line in the 64th minute and left Sitili Tupouniua in his wake to grab the try that took the Bunnies out to a 14-point lead with Mitchell's conversion.
Mitchell then put the icing on the Rabbitohs' first win of the season when he streaked away down the right touchline after a Roosters turnover on halfway was seized upon by Jaxson Paulo.
Paul Momirovski grabbed a consolation try for the Roosters but the night belonged to the Rabbitohs and their coach Jason Demetriou, who tasted his first win as a head coach.
Cameron Murray was a colossus for the Rabbitohs, running for 141 metres from 18 runs and making 44 tackles in a superb captain's knock. Angus Crichton gave the Roosters plenty of impact from the bench, making 115 metres from his 13 runs.
Joey Manu (one try, one try assist, seven tackle breaks) and Latrell Mitchell (135 metres, four tackle breaks) were the centre of attention in their first meeting since the infamous round 24 showdown in Brisbane last year. Both came up with some big plays but it was the Rabbitohs superstar had the last laugh on the scoreboard.
Damien Cook celebrated his 150th career game in style, making plenty of incisive runs out of dummy half and got through a power of work in defence with 43 tackles.
The Rabbitohs have now scored 168 points in their past four games against the Roosters.
Play of the Game
The Bunnies put the result beyond doubt in the 67th minute when Latrell Mitchell brought the red and green army to their feet with a runaway 55-metre try. A mistake by Joey Manu was swooped on by Jaxson Paulo who found Alex Johnston and then Mitchell to race away, saluting the crowd on his way to the line.
The Rabbitohs head to Penrith for a grand final rematch against the Panthers. Blake Taaffe (ankle) is expected to be available for the monster clash.
The Roosters travel to Townsville to face the Cowboys. In round 18 last year they took down the Cowboys 34-18 at Queensland Country Bank Stadium.