The side beat Hawke's Bay 84-83 in the preliminary quarterfinal of the under-19 national championships at the Edgar Centre.
Otago, which finished second in its pool, played the third-placed pool B team in a new competition format.
That earns it a quarterfinal spot against Wellington at 12.30pm today.
Also in Otago's pool was North Otago. A strong second half from Dallas Hartmann helped Otago overturn an early deficit to win southern derby 86-57.
However, North Otago had earlier thrashed Hutt Valley 104-54 to finish third.
It crossed over with Waikato A in its preliminary quarterfinal, but was edged 89-84 in a very creditable result.
In the other quarterfinals, Waikato will play tournament favourite Harbour A and Auckland will play Harbour B.
Waitaha Canterbury A will play the winner of the late game last night between Manawatu and Canterbury B.
On the women's side, Otago missed the top three of its pool.
It was left needing to win both games yesterday, having been thrashed by Harbour and edged by three against Canterbury on Saturday.
A 74-58 win over Manawatu yesterday morning left it on track. However, it was beaten 62-50 by Auckland Dream last night.
The pool was topped by Harbour and Canterbury which were playing for first and a direct route to the semifinal last night.
Two-time defending champion Waikato finished top of the other pool.
Games begin again at 9am this morning. The women's semifinals begin at 2.15pm and 4pm, while the men's semifinals are set for 5.45pm and 7.30pm.
