Wollongong and Keira will battle it out for Cricket Illawarra's first trophy of the 2023/24 season.
The Lighthouse Keepers and Lions progressed to next Sunday's T20 final after each team won one of the two games they played on Saturday.
Wollongong booked their spot in the decider first after they downed Keira by 20 runs in a thrilling contest at North Dalton Park.
The Lions though will get an opportunity to avenge this loss after they hammered Dapto by 66 runs in their second game on Saturday, paving the way for Keira to also qualify for the final.
Wollongong and Keira won four of the five games they played to finish the regular T20 season in the top two.
Wollongong T20 captain Jayden Zahra-Smith said it had been a great start for the club, adding the players were keen to win a title this season after losing last season's one-day final.
"The boys are really excited for the final. It's been a good start to the year even though we lost our last game against Port," he said.
"We're really excited for the final. I'm sure Keira will be tough to beat, as they were on Saturday."
Wollongong set up their win over the Lions with some lusty hitting at the top of the order from opener Ethan Debono, who hammered 29 runs from 23 balls and No 3 batsman Cooper Maddinson who smashed three fours and a six in his impressive knock of 34 runs from just 21 balls.
The Dodds brothers Toby and Callum also hammered the ball to all parts of the field, contributing quickfire knocks of 31 (from 18 balls) and 29 (19 balls) respectively to help Wollongong compile 5-152 from their 20 overs.
Ryan Cattle was the pick of the bowlers for the Lions, snaring 2-22 from his four overs.
Keira were well on track to chase down the total after their first three batters James Chappell (32) Eddie Manning (31) and Zach Churchill (35) contributed some quickfire handy top-order runs.
But the game turned Wollongong's way when Tobby Dodds got the ball in his hands.
No other Keira batsmen reached double figures as Dodds claimed the impressive figures of 3-18 from four overs to leave the Lions 20 runs short as they made 7-132 in reply.
"I thought we were really good against Keira," Zahra-Smith said.
"We need to be just as good if not better to beat them again in the final."
Having secured their place in the final, Wollongong were beaten by just six runs by Port Kembla in their second game under lights on Saturday at North Dalton Park.
Port made a respectful 9-138 batting first thanks to solid contributions from Steven Sutherland (23), Jack Yates (16), Harry Hobson (27), Praneeth Kumar Pudhota (16), Aamar Yasir (19) and Syed Nazeer (16 not out).
Cooper Bramley (3-25) and Zahra-Smith (2-24) were the pick of the bowlers for Wollongong.
Zahra-Smith also produced with the bat, compiling a well-made 26 at the top of the order.
Debono (23), Maddinson (26) and Pete Zybrands (22) also batted well for a Wollongong side which made 8-132 in reply.
Abdul haseeb Afridi (2-8) and Praneeth Kumar Pudhota (2-25) were the pick of the bowlers for Port.
Meantime in other round four results IPCC beat Northern Districts by two wickets and University passed Balgownie's total of 5-116 with an over to spare.
In other round five fixtures Northern Districts beat Wests Illawarra by five runs and Dapto hammered IPCC by 70 runs.
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