Gerringong Lions forward Hamish Stewart starred as the Dragons upset the Raiders in wet and wild conditions in Wollongong on Saturday night.

St George Illawarra displayed tenacity in the heavy rain and strong winds to get the better of first-placed Canberra 18-12 in one of their best performances of the season.

Stewart played a crucial role in getting the Dragons home - he was everywhere in the second half as the home side repelled the Green Machine's attacking raids.

He finished with 10 hit-ups for 85 metres and peeled off 20 tackles without missing any in the slippery conditions.

The match finished at two tries all but Kyle Flanagan kicked five goals, including three penalty attempts, to delight the hardy souls who braved the weather at WIN Stadium.

Ground officials closed the hill area due to the torrential rain with all spectators huddled into the three grandstands.

The Dragons have kept their slender playoff hopes alive but they still need to win their remaining five matches and hope other results go their way to pull off an unlikely qualification.

They opened the scoring when centre Mat Feagai crossed out wide after clever lead-up work from rookie five-eighth Lyhkan King-Tongia.

The Raiders responded via centre Matt Timoko touching down but the hosts went up 10-4 from a couple of penalty goals.

Timoko added a second to draw level at 10-10 heading into the break and with the wind at their backs in the second half, the Raiders looked like they would kick clear.

But despite running into a gale-force wind, the Dragons rolled up their sleeves to get the win with winger Corey Allan's try in the 55th minute proving decisive.

"Some of them could have been looking over their shoulder thinking we have been here before, and some nightmares might have come back," coach Shane Flanagan said about Canberra's late comeback which threatened to bring the Dragons' hard work undone.

"But to play like that in the last 20 minutes against the competition leaders was really pleasing. The attitude is there.

"Some sides don't have what I've got. I definitely know I have attitude and commitment. We could do with a bit more class here and there, but we have attitude and commitment, and I know a lot of other coaches wouldn't be able to say that."