Joining fellow senior player Jamie Whiteman at 191-9, the final pair put on a priceless 43 runs, including eight boundaries, by batting out the full innings and contributing 27 and 19 respectively.
Having only 10 available players, Tech needed a big score from someone in their top order, and while those batsmen contributed runs they also got bogged down as the United spinners began to tick the clock over.
Kane Watkin struck some promising boundaries before he fell to Whiteman on 19, while Caleb Greene moved into the 20s before becoming stuck against Tom Lance's spinners and the very close fielding ring.
After managing only a single from 28 balls, Greene was run out.
Lance finished with a very tidy 1-24 from his full 15 overs.
Skipper Dominic Lock, knowing full well he was shouldering the responsibility of Tech's innings, picked up the pace alongside Jessica Watkin, pulling some boundaries to move to 50.
At 115-3 after 34 overs, Tech still had a chance, but when spinner Robbie Power caught up with Lock just five runs short of his century, the writing was on the wall.
Power finished with 4-33 from 10 overs while United also made two run-outs as they cleaned up the Tech tail with two overs remaining.
Meanwhile, Collegiate will take a lot of confidence into their Gillette Cup game tomorrow with Wanganui High School after they beat Bayer Marist by five wickets at the school grounds.
Marist made 207 with Craig Thorpe (67) and Brett Cameron (55) the main contributors.
In reply, Collegiate were in trouble at 50-4, before Todd Inness scored an excellent century to see them through to the target.
While it was Marist's first defeat in the Premier League, the game was a non-points match so they will maintain their place at the top of the table.
Result
United 234-9 (T Lance 35, R Power 33, M Carroll 29, B Walker 27, J Whiteman 27no, J Watkin 3-42, D Lock 2-16, P O'Callaghan 2-56) beat Tech 184 (D Lock 95, J Roebuck 25no, C Greene 25, R Power 4-33, T Lance 1-24).