The Dragons remain in the race for a home final after posting a convincing 32-12 victory over a gutsy Penrith at WIN Stadium.
After taking a 12-0 lead into the sheds the Dragons suffered an early scare when Blake Austin scored for the Panthers with his first touch in the 52nd minute.
But there would be no second-half collapse from the premiers this time as Jamie Soward and Jason Nightingale crossed in the space of three minutes to open up a match-winning lead on the hour.
Brett Morris bagged a first-half double before the hosts ran in four-tries-to-two in the second half to take good momentum into the NRL finals.
The Saints will now await the results of the Tigers-Sharks and Warriors-Cowboys matches to determine their final ladder position and opponent in week one of the finals.
Wayne Bennett's men can finish as high as fourth and as low as sixth.
If the Tigers lose to the Sharks and Cowboys go down to the Warriors the Saints will finish fourth and host a home final, but if both sides win the Dragons will finish in sixth and face a likely showdown against the Broncos next weekend.
The Panthers' night was further soured by a pectoral injury to departing skipper Petero Civoniceva who is now in serious doubt for the Kangaroos Four Nations campaign starting next month.
Penrith set up camp in Dragons territory from the opening whistle but it was the hosts who posted first points when Morris crossed in the 15th minute.
Right centre Mark Gasnier cut inside before switching play for opposite centre Matt Cooper who put a step on Brad Tighe and delivered a one-armed pass for Morris to score the opener.
Soward added the extras from out wide for a 6-0 lead against the run of play.
Penrith enjoyed another period of dominance at the re-start but there was no way through the Dragons' brick-wall defensive line.
The Dragons were rewarded for their strong defence when Morris bagged his second four-pointer on the half hour to double the lead.
Adam Cuthbertson kept the play alive with a miraculous offload before Darius Boyd connected with left winger Morris who stepped past Walsh to score his second try in the corner.
The Panthers suffered more pain in the 32nd minute when Civoniceva's night ended with a pectoral injury as the Saints took a 12-0 lead into the sheds.
Penrith halved the deficit 12 minutes in when promising youngster Austin scored with his first touch after David Simmons batted back a pinpoint kick from Lachlan Coote.
The Dragons quickly reasserted their ascendancy with two tries in three minutes to Soward and Jason Nightingale to make it 22-6 on the hour.
With only pride to play for, the Panthers refused to surrender and hit back through Coote on 65 minutes.
But when Cooper scored off a Soward kick the contest was over with 10 minutes left on the clock.
St George Illawarra 32
Tries: Morris 2, Soward, Nightingale, Cooper, Rein,
Goals: Soward 4,
Penrith Panthers 12
Tries: Austin, Coote,
Goals: Walsh 2,
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