Avondale will get the chance to make up for last year's grand final heartbreak after accounting for title-holders Shoalhaven 32-19 in Saturday's final at Vikings Field.
The Wombats have booked a premiership showdown with Tech Waratahs, who won the minor premiership and will start as favourites.
"We're over the moon to be back in the grand final," Avondale club captain Andrew Tink said.
SLIDESHOW: Weekend sporting action"Losing last year was very disappointing, but a lot of guys learned a lot and last year's experience should serve us well."
That the Wombats reached the grand final at the expense of Shoalhaven - emphatically outscoring them five tries to one - only amplified their joy.
"They've been our bogey side for a few years so it was good to knock them out," Tink said.
Shoalies started strongly on Saturday and were protecting a 16-12 lead late in the first half.
But Avondale scored a minute before half-time to forge ahead 17-16 at the break and kept their try-line intact for the entire second half.
"We came out flat the week before in the major semi-final against Tech, but the effort was there against Shoalhaven and you could tell in the warm-up that the boys were really up for it," Tink said.
"We've had a lot of sickness running through the club at the wrong time of the year and it made training disjointed last week because we didn't know who would play and who wouldn't play.
"But the guys put all that aside because they were really hungry to make the grand final. Their attitude was spot on and they really stuck together. They knew there was no second chance and they stuck to their guns for 80 minutes and closed it out."
Avondale's points came via tries to Trevor Patrick, Ian Ross, Chris Jack, Chris Creber and Chris Tausala, while Jacob Hurst kicked two conversions and a penalty goal.
Sam Watts scored Shoalhaven's only try, with Leith Cooper booting three penalties, one conversion and a field goal.
"They were better on the day. We had some opportunities but we just didn't take them," Shoalies co-coach Chris Watts said.
"Considering the injuries we had this year when we had 22 blokes out at one stage in first and second grade, the boys did really well to get this far. But they're disappointed that we're out. Losing never gets any easier."
The Wombats went narrowly close to repeating last year's feat of having three teams in the grand final, losing Saturday's second grade final 20-19 to Camden and the third grade final by the exact same score to University.
"We were very happy to win the club championship again, but obviously we're very disappointed our second and third grade boys won't be playing on grand final day, especially after they both only lost by a point," Tink said.
"Everyone got through the game unscathed so we should have our full 15 available next week. Tech are a good team, but if we play to our potential we'll definitely back ourselves 100 per cent to get the result we're after."
Grand final draw for Saturday's grand final at WIN Stadium: Third grade, noon - Shamrocks v University. Second grade, 1.25pm - Vincentia v Camden. First grade, 3.05pm - Tech Waratahs v Avondale.