Otago were down to 14 men at the time, their left wing Keiran Moffat having been sin binned by the other Japanese influence, referee Akihisa Aso, for a mid air tackle.
The zero to hero moment was provided by Otago fullback Buxton Popoali'i. It was Keystone Cops time as a bouncing ball sailed over his head, but he produced a mighty recovery to rob No. 8 Huia Tevita Koloamatangi of the ball over the tryline.
Tasman had a 20 - 13 lead at the break, but probably deserved better. Tasman's scrum crushed Otago's on occasion, and they held an edge elsewhere, but the visitors stayed in touch.
Tasman found a ruthless attacking edge to ram home their advantages in the second half, finishing with another stunning try initiated by Marshall. Tasman have a powerful set piece foundation and a well controlled attack that probably marks them as the championship favourites.
Tasman 49 (James Lowe 2, Liam Squire, Shane Christie, Huia Tevita Koloamatangi, Mitchell Scott tries; Marty Banks 5 con, 3 pen)
Otago 16 (Craig Miller try, Hayden Parker 3 pen, con). HT: 20-13.