Otago beat Manawatu-Wanganui 4-1 in the morning and disposed of Northland by the same margin in the afternoon on a day that was fine but breezy.
The top trio led the way with two wins each while No 4 Laura Hoskin and No 5 Jo Hicks-Beach emerged with one win apiece.
Otago No 1 Monica Tulisi was always in command in her morning match against Maraea Durie, eventually winning on the 14th green.
No 2 Lisa Henderson trailed by two after 11 holes but rallied to win five holes in a row to close off her match with Keita Durie on the 16th green.
No 3 Shani Arona also was behind at the turn but made a spirited comeback on the homeward nine to win on the final green.
Hoskin was always down to Carol Leary in her morning match and lost on the 16th green, while Hicks-Beach played well on the homeward nine to come from behind to win on the final green.
In the afternoon, Tulisi turned one behind Northland's Phoebe Perrin but birdied 12 and 13 on the back nine and took the match when Perrin had bunker trouble on the 16th and 17th holes.
Henderson made a solid start, turning 3-up on Aroha Tito, and was 4-up after 12 holes.
She lost 13, 15 and 16 but made a good par on the 17th to close out the match when Tito failed to get up and down.
Arona was square after nine holes in her afternoon match but parred home to beat Sam Dangan 3 and 1.
Hoskin turned 1-down in her second match but was more consistent than Northland's Jo Wech on the back nine to win on the final green.
Hicks-Beach turned ahead in the afternoon but Sjanna Bonnington fired on the homeward nine to win on the 17th green.
This morning Otago will meet Tasman but will need a decisive win to retain the division two lead as the team has a bye in the afternoon.
Wellington joined Otago as the only other team to achieve two wins, despite having to dig deep to grab its victories by the closest of margins yesterday.
The home team, with No 1 Lucy Davis the oldest player at 20 years, is trying to become the first Wellington side in nearly two decades to win the interprovincials.
It edged Hawkes Bay-Poverty Bay 3-2 in the first round and then fought off a strong Canterbury combination to win 3-2 in the second round.
"That was two really tight games and an outstanding result for us," Wellington coach Dylan Lindstrom said.
Defending champion Auckland and runner-up North Harbour, after the morning bye, steamed their way through their afternoon encounters.
Harbour was a 5-0 winner over Manawatu-Wanganui, while Auckland, without star Cecilia Cho until today, won 4- against Southland in its first clash.
The 14 district teams are divided into two sections with section play continuing until Friday. The semifinals and final are on Saturday.
