Monica Tulisi continued her winning form at No 1, playing immaculate golf to trounce Stephanie McKillop in 13 holes.
Kathryn Fletcher at No 3 posted her first win, winning five holes out of six on the homeward run to beat Jaimee Lee Morrah by a convincing 5-4 margin.
Wakatipu schoolgirl Shani Arona had her first win at this level after two final-green losses yesterday.
She beat Tracy Corbett in 16 holes.
Otago's last win came in 2005, when it beat South Canterbury 4-1.
But celebrations were short-lived, with the team copping a 5-0 drubbing from tournament favourite Waikato in the afternoon.
Tulisi has three wins from four games at No 1 and is becoming one of the stars of the tournament.
In her morning match she was four up at the turn, and took the 12th and 13th holes to secure the win.
In the afternoon Tulisi faced a tough opponent in Emily Perry, St Peters School in Cambridge, and lost on the final green after bogeying the 18th.
Liz McRae (No 2) was two up at the turn in her morning match but lost the next four holes to Maraea Durie to lose the match.
In the afternoon McRae was no match for Erin Hawe, going down by a 5-4 margin.
Fletcher dominated on the back nine for her first win in the morning but failed to take her chances in the afternoon.
Julie Cooper, the Otago No 4, was four down at the turn in her morning match and staged a good fightback to trail by one with two holes to play.
But she lost the 17th to Kelly Nicholas and the match finished on the final green.
Arona overcame her first-day nerves for her morning win and made a good start to her afternoon match to lead Charlotte Brooks by two after the first three holes with birdies at the second and third.
But she turned three down after Brooks fought back and she never recovered.
Auckland moved a step nearer a place in the semifinals with a win over Aorangi-South Canterbury.
Auckland's 3-1 win left it the only unbeaten side in section one after four rounds.
Defending champion Bay of Plenty had its first loss yesterday, tripping up 3-2 against a North Harbour with an average age of 15 and boasting three newcomers.
North Harbour, with Lydia Ko (11) still unbeaten, banked its third win, at Canterbury's expense, in the fourth round, while Bay of Plenty accounted for Wellington 3-1.
Auckland and Bay of Plenty play a crunch match this afternoon, while North Harbour still has to play Aorangi-South Canterbury.
In section two, Waikato and Hawkes Bay-Poverty Bay both continued their winning ways.
