Earlier in the week the club's men's and women's pairs also qualified for the national finals to be held in Rotorua next month.
The men's team of Billy Cosgriff, Steve Jones and Danny Rooney beat Alexandra's Trevor Ludlow, Pat Houlahan and Bill Clements on the differential at the North East Valley green.
Both teams had four wins and one loss but the South Canterbury team had a differential of plus 39, compared with Alexandra's plus 23.
Geraldine beat Alexandra 19-8 in the first round to force the Central Otago team to play catchup bowls after that. Geraldine also beat Clinton 27-6, Waihopai (Southland) 16-12 and Leith 25-11.
It conceded its final game to the North Otago club Pukeuri 6-11, when it knew it had the differential edge over Alexandra.
Features of the Geraldine performance were the lead bowls played by Billy Cosgriff, who was never far from the jack, and the accuracy of Jones in the middle.
Rooney, an aggressive skip, added the extra shots and played telling upshots when opponents controlled the head.
Alexandra rallied after its first-round loss to win its last four games against Leith, Pukeuri, Clinton and Waihopai but was not able to catch Geraldine on the differential.
The Geraldine women's combination of Marion Patrick, Pam Shirtcliff and Bett Prattley remained unbeaten with four wins and a 19-19 draw against the St Clair combination of Daphne Hynes, Trish Marr and Carolyn Webster.
The team is skipped by former New Zealand representative Bett Prattley, who represented New Zealand in the 1990s and won a bronze medal in the fours at World Bowls in 1996 and a gold and silver medal at the Asia and Pacific championships in Dunedin in 1995.
Patrick and Shirtcliff put in the early bowls and Prattley added the extra shots and disrupted the head when her opponents were on top.
The Geraldine team has been playing together for 10 years and has dominated South Canterbury women's bowls during that time.
Prattley has won a record 31 centre titles, Patrick 25 and Shirtcliff 17.
Shirtcliff (76) has been playing bowls for 25 years and is the oldest player at the regional qualifying event.
Geraldine had to win its fifth-round game against Jenni Heazlewood's Arrowtown to win the tournament.
It scored 12 shots from the fifth to the 11th ends to lead 14-4 and eventually won 20-11 It also beat Lawrence 21-11 Georgetown (Southland) 18-15 and Weston 19-14.
Geraldine won the event with four wins and a draw from Georgetown (four wins and a loss and differential of plus 28) and Dunedin (four wins and a loss and differential of plus 22).
The fours start at the Logan Park greens today.
