Tasman won 54-19 after leading 28-12 at halftime and running away with the game in the second half.
The home side, with plenty of Super Rugby players, ran in eight tries to Otago's three, and was always in control in what was the final pre-season game for both teams.
Rain fell just before the kick-off, but it did not deter either side, and as some class players entered the game in the second half, the home team took control.
Otago coach Ben Herring said Tasman showed the standard that was needed to compete in the top levels of Mitre 10 Cup.
Otago had started well, he said, and the first 30 minutes it had competed and matched up with Tasman. In fact, it scored the first try of the game through captain and No8 Dylan Nel.
But the home side had too much class and ability, pulling away from the visitor.
"It blew out at the end, but we had a couple of props out on the wings and a hooker playing No8. That wasn't the way we wanted to finish, but they kept coming at us," Herring said.
Otago ended with plenty of injured troops and had players well out of position in the final few minutes.
Halfback Kurt Hammer appears the most serious injury after he got a whack on the arm just after he had come on in the second half.
He had his arm in a sling after the game, and it would be assessed over the weekend.
Other players had picked up knocks and with the first round of the competition next week, Herring was mindful to take care of some key players.
The first 30 minutes from Otago was good and Vilimoni Koroi made a good fist of things in the first five-eighth position, Herring said.
Koroi, along with Jona Nareki, left the field in the second half, but that was mainly to protect them for next week.
Otago lost direction in the second half and was chasing attackers at the end.
Liam Squire made an impression, as the All Black came on to the field for the second 40 minutes and made a couple of strong runs.
It took until the 20th minute for Tasman to get on the board when fullback and captain David Havili broke the line and linked with Crusaders teammate Will Jordan for Tasman's first try.
Jordan quickly scored another, but then Otago prop Aki Seiuli powered his way over the chalk to bring his side within two.
Tasman though took over the game and pushed the score well out in the second half, although Otago winger Taylor Haugh swooped on a Finlay Christie error and sprinted 80m for a late consolation.
However, the Makos did have the final say as Alex Nankivell ran a superb line off O'Malley to seal a dominant win.
Otago v Tasman
The scores
Tasman 54
Will Jordan 2, Leicester Faingaanuku 2, Andrew Makalio, Liam Squire, Hugh Roach, Alex Nankivell tries, Mitch Hunt 5 con, Tim O’Malley 2 con
Otago 19
Dylan Nel, Aki Seiuli, Taylor Haugh tries; Josh Ioane con, Haugh con Halftime: 28-12
