It was a replay of last year's final at Balmacewen, when the Bay team won in a playoff, but Manawatu-Wanganui made no mistake this year.
Josh Munn, Tyler Hodge, Lachie McDonald and Hayden Ring all won their matches while Trent Munn was held to a half by Victor Janin.
McDonald had six wins and a half during the tournament and, although Jordan Bakermans (Canterbury) and Peter Lee (Bay of Plenty) had better statistics, Lachie McDonald was named player of the tournament for responding for his winning team at crucial moments.
The Manawatu-Wanganui win was popular, as the province last won the then-Freyberg Rosebowl in 1964, on its home course.
Otago finished fourth, after losing the morning semifinal to the Bay golfers, who were always in command.
Otago started slowly and was to pay the price, as all five Bay of Plenty players were very clinical, feeding off Otago's mistakes and giving little in return.
The team was without the services of No 2 Nick Borren, who left the team on Friday evening to be best man at the wedding of former Dunedin rugby player David Thompson, on the Kapiti Coast.
This brought reserve Kayne Wardell into the team and the last three players were all promoted one place.
Wardell lost the first hole, struck hazard trouble on the third and three-putted the fourth green to trail by three early.
He won his first hole when Charlie Hillier went out of bounds at the fifth but the deficit was back to three when the pair turned for home.
Hillier won two of the next four holes to be dormie five up and the match finished on the next hole which was halved in pars.
No 4 Mark Brooks had a good winning record in the section play and looked set to continue this trend when he had a tap-in eagle 3 to take the lead on the second.
He lost the third to a birdie 3, the fourth to a par 3 then the fifth and sixth holes, to go three down.
He turned three down, won the par 5 10th but lost 11, 13 and 15 to lose with three holes to spare.
Jamie Anstiss was the most competitive of the Otago players but still found himself three behind after first eight holes.
He birdied the ninth to turn two behind and after some see-sawing, was two down with three holes to play.
Anstiss kept the match alive with a birdie 3 on the 17th and birdied the par 5 18th, only to be matched by William Howard and lose 1-down.
Sean Masters was promoted to No 2 and played well on the front nine only to three-putt the ninth green to turn square with an unbeaten Sam Davis.
Once again the 13th and 15th holes were his nemesis, putting him three down with three to play and the match finished on the 16th green.
Brent McEwan (No 1) has been a stalwart of Otago golf but had one of his most forgettable interprovincial experiences this year.
He met an in-form Peter Lee and lost seven of the first eight holes. He won the ninth to turn six behind.
It was a tough ask to come back from that position against one of New Zealand's top golfers and the match finished on the 12th green.
