Otago last won the cup in 2010, when the event was also played on the hilly Otago Golf Club course.
The host team took advantage of local knowledge and took a tidy lead at lunch with five wins and one half from the eight reverse singles games.
However, the Southland octet retaliated in the afternoon, posting four wins and two halves to almost make up the morning deficit.
The 8 to 7 win was a boost for the Otago team leading into the South Island teams event to be held at Russley on November 5-6.
For Otago, No1 Abigael Crawford emerged unbeaten with two halves and Rachel Lissaman had one win and one half.
But the Otago tail duo were the heroes of the day: Kate O’Connell (Ardleigh) and Becs Calder (Omakau) won both of their games.
For Southland, Olivia Frost had two wins and Robyn Pullar and Jody Drysdale had a win and a half each.
In the afternoon battle between the No1 players, Crawford and Angela Gerken had a seesaw match in which Gerken was three ahead after the infamous Glen hole.
Crawford won 12, 13, 14 and 15 to take the lead but Gerken sank a lengthy birdie putt on the final green to snatch the half.
Annabel Evans (No2) won her morning match but struck Robyn Pullar, who played the last four holes three under par to give Southland a 4 and 2 win.
At No3, Danielle Bailey had an impressive win in the morning at the expense of Helen Baird but she lost to Olivia Frost on the final green after being penalised for a bunker infraction.
In the afternoon, Otago was struggling to get the required three games in, even after the tail pair posted good wins.
A long cross-green lag putt on the final green by Lissaman all but went in and she grabbed the deciding half when Drysdale three putted.
