The Bulldogs looked no chance of breaking their 2008 duck when trailing 12-0 just 20 seconds out from half-time, but three tries sandwiched around the interval had the visitors up 18-12 six minutes after the restart.
From there the Bulldogs renowned defensive wall clicked into gear, at one stage repelling the Rabbitohs for five straight sets as the home side looked for some way back into the match.
The Bulldogs showed them how it was done when Luke Patten raced over for the match-winner on the back of a Daniel Holdsworth inside ball, the second half comeback a complete reversal of their round-one capitulation, when they surrendered a 20-0 half-time lead to Parramatta.
The loss leaves Souths 0-2 and struggling to put points on the board without injured playmaker Craig Wing; coach Jason Taylor with more than a few headaches as he looks to come up with a winning combination.
Without the injured Sonny Bill Williams the Bulldogs started slowly, Souths capitalising on their dominance in position and possession when debutant Ben Lowe was turned back inside by Ben Rogers for a 6-0 lead after 19 minutes.
The Bulldogs kicked out on the full from the restart but it was a crucial call from the video referee that really hurt them, a knock on against the Bunnies changed to a penalty on review from the man upstairs.
Half-back Eddie Paea sliced between Andrew Ryan and Jarrad Hickey on the next set before crawling over the line for a 12-0 lead, the Bulldogs appearing dead and buried before their stunning form reversal.
It started with winger Matt Utai, who took advantage of a poor defensive read from opposite Merrit 20 seconds out from half-time before the pumped up Dogs went over twice in the north-western corner after the break via Willie Tonga and Tim Winitana to open the second stanza.