In years to come, the game might well be best remembered for the debut of teenage prodigy Payne Haas.
The 18-year-old reinforced his star qualities with an outstanding debut for the Broncos.
The 194cm, 117kg giant ran for 86 metres despite only being on the field for 21 minutes.
"You're seeing the birth of a superstar," Phil Gould said on the Nine Network commentary.
The Broncos have concerns over Josh McGuire, with the lock-cum-hooker spending most of the second half on the bench with an ankle injury.
The Broncos looked in control for much of the second term, however a John Sutton try in the 64th minute set up a grandstand finish.
The Rabbitohs threw everything at the Broncos in the final 10 minutes but couldn't come up with a match winner for skipper Greg Inglis in his 250th first- grade game.
Kodi Nikorima, who was dumped last week from the starting side, sparked the Broncos off the bench.
He was controversially denied a try by the video referee just before the break as the home side carried a 12-6 halftime lead, thanks to an Alex Johnston runaround play.
But the Broncos' super sub evened up the scores in the 50th minute when he darted between Sutton and Cody Walker.
Winger Corey Oates was also outstanding, running for 213 metres and scoring a barnstorming try in which he beat four defenders when there appeared to be nothing on.
Oates' try gave the Broncos the lead for the first time before Anthony Milford displayed his vastly improved kicking game with a deft grubber for a flying James Roberts.
Earlier, it took just seven minutes for the Rabbitohs to strike first when Jack Bird made a mess of an Adam Reynolds grubber and Walker pounced on the spoils.
The Broncos evened things up when Milford ran it on the last and Oates beat Richie Kennar in a race for the ball.
But many believed scores should have been level after the bunker controversially ruled Nikorima had been held up by Johnston, despite some evidence he had grounded the ball.
Broncos coach Wayne Bennett revealed he pulled prop Matt Lodge because he was off his game, effectively leaving them with two men on the bench after losing McGuire.
On Haas, Bennett said: "You've got to get your kids ready at some stage and start the process.
"Obviously Payne's going to be an NRL player for a long period of time.
"It's just getting him into the game and how you do that and try and manage that. Because I don't want them to get ahead of themselves. At the same time I want him to be able to handle the situation as well.
"He's been in the state league for a while and he'll probably spend a few weeks on the interchange bench and maybe then we'll make another decision."
Souths coach Anthony Seibold revealed winger Richie Kennar had suffered a potentially season-ending ankle/foot injury.
"We've improved, we've shown signs of our potential," Seibold said of Souths' first third of the season.
"The last five weeks I've been relatively happy, we've been building strongly and we took a step back tonight I thought.
"Particularly in that second half, we went three from six in the first 20 minutes and didn't give ourselves a chance. That hasn't been us in the earlier games."