Corrimal won two of the three rinks against Kiama to claim the annual Reg Evans Shield at Fairy Meadow Bowling Club.
Both clubs would have been considered outsiders at the start of the four-week event but upstaged some of the bigger clubs to each win four rounds and meet in the final.
Eric Johannes skipped his Corrimal triples team to a 17-12 win over Keith Pepper, while in the key rink of the grand final, Paul Sweeney (Corrimal) drew a shot with his last bowl to beat Mick Ganderton 14-13 in the fours.
Had the match finished in a draw, Kiama would have had a chance of taking the title as they led by three shots with two ends to play in the pairs.
Kiama's Geoff McIntyre went on to win the pairs, 14-13, against Trent McMillan, with the final end not played.
The tournament was played over four weeks on a Tuesday and Thursday night in honour of former Illawarra Zone 16 secretary Reg Evans. This year the format was pairs, triples and fours.
Corrimal advanced to the final with a 4-2 win over Albion Park in their semi-final, while Kiama also won two of the three rinks in a tight 4-2 win over Thirroul No 1.
In the quarter-finals, Albion Park beat Bulli No 1 on overall shots after both clubs won one rink each and drew a rink.
The Park's fours skip Mick Duprez clinched a draw against Steve Haines with his final bowl, with the result proving critical in the Park advancing to the semi-finals.
Kiama were missing some of their best players but advanced to the semis with a 4-2 win over Fairy Meadow No 4.
Corrimal beat Woonona 4-2 in their quarter-final, while Thirroul No 1 won two of the three rinks in a 4-2 win over Fairy Meadow No 1.