They raced the ball back to the 20m line then shifted the ball quickly to the left to create an overlap, outnumbering the Rabbitohs defenders as the ball ended up in the hands of Tim Lafai, who raced 70 metres to score.
They had the extra man because they attacked right where Auva'a would have been defending had he not been helping Nightingale - the Samoan international not at his customary right centre position. South's defensive edge was then left exposed and he couldn't return to the flank in time to thwart the near length-of-the-field effort.
That gave the Dragons a 10-4 lead in the 26th minute before the Rabbitohs hit back with two tries before the break to go into half-time ahead 14-12.
Souths temporarily moved back into the NRL top eight courtesy of a questionable try to second-rower Paul Carter in their 34-24 win over the Dragons.
The Rabbitohs led 20-18 with 18 minutes to go when Carter planted his hand on an Adam Reynolds grubber. It was missed by teammate Sam Burgess and, according to the bunker, not grounded in-goal by Dragons fullback Josh Dugan.
Replays showed a small knock-on by Carter in the lead-up, however Bryson Goodwin sealed the win by taking another Reynolds kick - his third try assist of the night - in the 74th minute. In his final outing before the naming of the NSW State of Origin team, Reynolds then kicked an 80th-minute penalty, becoming just the fourth player in the foundation club's history to crack the 800-point mark.
In front of a crowd of 12,054 at ANZ Stadium, the Rabbitohs overcame a horror night with the ball to register back-to-back wins and leapfrog the Dragons into the top half of the ladder.
Tom Burgess turned the ball over in the opening set of the game that resulted in a second-minute try to Jake Marketo, while Sam Burgess and Reynolds also dropped the ball inside the opening 15 minutes.
Third brother George also lost his marbles seconds into the second half.
However, led by the pinpoint kicking of Reynolds, the Rabbitohs showed great resolve, twice coming from behind in the first half to take an unlikely 14-12 lead into the sheds.
Utility Cody Walker - the Rabbitohs' third fullback in as many games - scored a sublime individual try on the stroke of half-time to rub out a poor opening 40 minutes by the team.
Opposition pivots Gareth Widdop and Greg Inglis traded highlight-reel plays in the space of just seven minutes, Widdop first showing quick hands to send Tim Lafai on an 80-metre run, before Inglis returned serve with a 30-metre cutout for Dane Nielsen.
- with AAP
