However, Saracens had plenty of spin options themselves but could not prise out the wicket of young United opener Chris Sharrock, who probably would have liked more of a target to chase as he carried his bat through to an undefeated 91.
With Hobbs and Power playing support at each end of his innings, Sharrock insured United were never in any real danger, having reached a slow but steady 93-1 after 25 overs, and despite a couple of wobbles from losing two quick wickets, were well in the box seat at 129-3 after 37.
"He's batted really well all year and that's satisfying, just a shame he couldn't get the 100," said Carroll of Sharrock's innings.
"He's come on leaps and bounds."
Marton ended up expediting their own demise with dropped catches from skied deliveries and offering overthrows to United's two quickest batsmen between the wickets in Sharrock and Power.
Carroll was pleased to have wrapped up the 50-over title again, especially as United had lost the services of key men like Andrew McCaa and Andrew Cording (left town) and Tom Lance (injury) this campaign.
"It's satisfying this year with the younger guys, it's good to get it done."
United will now head to New Plymouth to take on the Taranaki club champions this Saturday, which was to be the winner of yesterday afternoon's final between Woodleigh and New Plymouth Old Boys.
The Taranaki sides have long had the wood on United in the inter-association challenge, although Carroll recalled last year's five-wicket loss to Marist United went down in part to poor fielding, which is a facet they have worked on.
Across the park, Bayer Marist got some compensation after a disappointing one-day campaign with an unbeaten Brett Cameron century guiding them to a six-wicket win over St Johns Tech.
Thanks to good scores from Nick Harding and the Lock's Tyler and Dominic Tech looked to be getting into good position at 164-4, before Marist bowler Sam O'Leary sparked a mini-collapse by picking up two wickets in consecutive balls and being turned down for a close LBW shout on the hat-trick delivery.
No doubt stung from missing selection for the 15-man New Zealand Under-19 world cup squad, Nick Blundell bowled aggressively to pick up a couple of wickets for Marist.
Tech did recover, aided by Marist conceding a few extras, and claimed 17 runs off the final over despite being bowled out to give themselves a solid target to defend.
But Cameron was in very good touch sharing in an opening stand of 47 with Todd Inness (20), then carrying on with Craig Thorpe (52), with the winning runs being hit in the 44th over.
Results:
Marton Saracens 185 (D Rayner 79, D Ford 22, R Power 3-38, G Hobbs 2-31, J Whiteman 2-23) lost to United 186-3 (C Sharrock 91no, R Power 24no).
Tech 233 (D Lock 41, N Harding 40, T Lock 37, N Blundell 2-30, S O'Leary 2-43) lost to Marist 234-4 (B Cameron 111no, C Thorpe 52).
