St George Illawarra’s NRL finals hopes are on life support after South Sydney snatched a come-from-behind 26-24 win against their traditional rivals at the SCG.

The Dragons appeared home on Friday when Nene Macdonald crossed to give them a 10-point lead with 10 minutes remaining.

But the Rabbitohs scored two tries in the final five minutes and halfback Adam Reynolds nailed a sideline conversion to steal a famous win.

The defeat for the Dragons opens the door for ninth-placed Penrith to move into the top eight should they win beat Wests Tigers on Sunday.

Paul McGregor’s side have now lost four of their past five games.

Compounding the heartbreaking loss – their second straight to a bottom-eight team following last week’s upset to Newcastle – was a first-half ankle injury to star Josh Dugan.

The pressure of the finals race seemed all too much for the Dragons from the start after committing six errors in their opening 12 sets to be down 12-6 at the 23-minute mark.

Jason Nightingale opened the scoring, however the Rabbitohs responded with back-to-back tries to Alex Johnston and Damien Cook.

Johnston broke out of some flimsy fringe defence to score his league-leading 17th try of the season, before he threw an inside pass for Cook to power over.

But the introduction of Tyson Frizell turned the momentum the home side’s way, with the NSW State of Origin star producing an offload that set up a Joel Thompson try in the 34th minute.

Frizell was then denied a try-scoring opportunity when he was tackled close to the line, resulting in Rabbitohs captain Sam Burgess being sent to the sin bin.

Kurt Mann made it a six-point advantage at halftime when he finished off a Josh McCrone crossfield kick which was batted back by Nene Macdonald.

The Rabbitohs had an opportunity to level the scores after the resumption but took the bizarre option to kick a penalty goal despite Burgess nearing a return to the field.

Macdonald seemingly sealed a Dragons win until John Sutton’s opportunistic try in the 75th minute paved the way for Bryson Goodwin to score during the next set.