Mooney described the game as a "good work-out" and put the 26-point victory down to a solid performance from the forward pack and some fast ruck ball.
"Under the circumstances, it was a pleasing hit-out and the opposition were obviously a step up from the previous week," Mooney said.
Otago dispatched North Otago 78-9 last weekend and lifted a notch from that performance with some dominant play in the forwards.
"The forwards set a really good foundation in the first half. They gave us some good front-foot ball and Tony Brown controlled it well and guys like Ben Atiga and Buxton Popoalii were able to capitalise on it that."
The visiting side wasted little time getting on the scoresheet, with winger Joe Hill dotting down after eight minutes.
Lock Tom Donnelly scored the first of his two tries a few minutes later and then both props helped themselves to a tries.
Halani Aulika crashed over in the 21st minute and former All Black Kees Meeuws scored after 27 minutes.
Otago led 31-5 at halftime but Tasman gained some parity, scoring two tries and restricting Otago to 14 points in the second spell.
"They sort of ran on two completely different teams - with a first-half team and a second-half team," Mooney said.
"So in that regard, it was a good work-out for us because we only had the 24 players which meant, in the second half, when we were fatigued, we had to really work hard and concentrate to maintain our shape. I thought we did that pretty well."
Otago came through the encounter unscathed other than "the normal knocks and bruises" and Mooney was pleased with his side's application.
"We travelled up here on game day so it was a long day. But it replicates, to a degree, what the tournament will be like with short turnarounds. So it was a good mental rehearsal for the boys.
"We'll be working on fine-tuning elements of the attack and defence.
" For some of the guys that was their first game for Otago, so it is just furthering the development of those combinations."
Otago plays Southland in Invercargill on Friday night. It is its last pre-season game before the ITM Cup opener against North Harbour at Carisbrook on July 14.
Southland will certainly present a tougher challenge than Tasman, and it is the first time the two teams have met since the controversial Ranfurly Shield challenge in which the home side held on for a 16-12 win.
The scores:
ITM Cup pre-season
• Otago 45 (Tom Donnelly 2, Joe Hill, Halani Aulika, Kees Meeuws, TJ Ioane, Buxton Popoalii tries; Glenn Dickson 5 con)
• Tasman 19 (Shaun Begg, Mark Bright, Sione Holani tries; Daniel Hawkins, Andrew Goodman con)
• Halftime: 31-5
