An ankle injury put his season in doubt a week ago and his night was stymied by two bombed tries, but Panthers back-rower Liam Martin stood up when it counted, capping his miraculous recovery with the defending premiers' match-winning try in the last two minutes.

"It's been a tremendous three-year period for the club," Panthers coach Ivan Cleary said, reflecting on securing another minor premiership with two games to spare.

"Having said that, when we start the finals in two weeks' time (the minor premiership) is not going to mean that much."

Still without three of their best in Nathan Cleary, James Fisher-Harris (suspensions) and Jarome Luai (knee injury), the task was lofty for Penrith on Thursday night.

The Rabbitohs, virtually at full strength, had lost just once since Latrell Mitchell's recovery from his hamstring injury (in golden point) and had averaged more points than any other side in games since the representative round.

But, inspired by their own fullback Dylan Edwards' return from injury, the Panthers rediscovered the physicality that eluded them against Melbourne last week and took it up to the Rabbitohs in a match of finals-like intensity.

Penrith had the mental edge early when Stephen Crichton pounced on a wayward South Sydney pass and streaked away for an intercept try - just as he did against the Rabbitohs in the 2021 Grand Final.

The Rabbitohs announced their intentions to attack wide and struck back through winger Alex Johnston, who has now scored at least one try in each of his last seven games.

Errors began creeping into South Sydney's game just as they did earlier in the season but both sides blew their share of chances.

Martin bombed two tries in goal, while Souths winger Jaxson Paulo coughed the ball up twice on the burst and knocked on in goal himself.

The Panthers looked ready to go on with the contest after Spencer Leniu pounced on the ball in goal, which had been knocked back by his old rival Jai Arrow.

But the Rabbitohs' famous edge attack produced two tries to keep Souths in the fight, the second coming after some classy quick hands from Cody Walker allowed Johnston to dot down for his second try.

When Paulo knocked on yet again in the danger zone, the Panthers were in position to secure a heart-stopping win.

"There have probably been three or four games this year where in the dying stages, we've come up with individual errors and on the back of those conceded points," lamented Rabbitohs coach Jason Demetriou.

"It's something we need to fix going into the big games."

It was a mixed night for superstar Mitchell, who was made to work harder at the back than he would have liked by Sean O'Sullivan and his long kicking game.

Mitchell threw a beautiful ball that helped Souths equalise just before halftime and slotted the sideline conversion that gave the Rabbitohs the lead for the first time with 10 minutes to play.

But he came up with some hospital passes that put serious pressure on his teammates, particularly when the game was in the balance late.

"That's what (the Panthers) do, they put pressure on you in the back of the field," Demetriou said.

The loss all but confirmed South Sydney won't finish the season in the top four.

Australian Associated Press