However, wickets fell at the other end with only Jamie Simmons (12) reaching double figures, and when Trillo was bowled by Simon Badger (2-30), the writing was on the wall.
The last four wickets fell for six runs, with Walker cleaning up the tail to finish with 4-9 from his 7.4 overs, as Marton folded for 149 in the 39th over.
In reply, United racked up a 114-run partnership for their opening wicket, as Allistar Bostock (25) supported captain Tom Lance (74), who was in classic form with seven boundaries and two sixes in his 79-ball knock.
While Michael Thomson (2-19) managed to get both of them over the space of four overs, it was a simple matter of Greg Smith (21no) and Chris Sharrock polishing off the remaining runs to have the match wrapped up before the end of the 30th over.
"We're happy to get [Wingnut] back," said senior team member Gerrard Hobbs.
"We didn't bowl very well, we've got a lot of work to do with our bowling.
"We got the runs pretty easy in the end. Tommy hit them quickly."
United will now go on to a top of the table clash with Marist, who picked up a three wicket win over Wanganui Collegiate in the schoolboys first game back in Premier 1 competition.
Not used to playing at Springvale, Collegiate worked through to 147-7 in 40 overs of the weather-shortened match, led by a determined 58 not out from No3 batsman Ben Kelt.
Nick O'Leary chipped in with 21, and while no other Collegiate batsmen made a notable score, all of the middle to lower order reached double figures to give themselves something close to a defendable total under the circumstances.
"I thought they did very well. It wasn't easy on that artificial," said coach Warren Marr.
"Ben Kelt made an exceptional effort."
Marist's Greg Hamilton, John McIlraith and Michael Gill took two wickets each.
In reply, Marist reached their target at the end of the 38th over, 151-7, being almost solely reliant on their captain Mark Fraser with an anchoring 72 not out from 79 balls.
Fraser hit five boundaries and four sixes, getting several of them during a key two over stretch to take the initiative away from the schoolboys.
Other than McIlraith, who made 31 before being caught and bowled by Connor O'Leary (2-30), no other batsman made a big contribution, with the next best being Kent Darlington making 11 from 38 balls to stay with Fraser for as long as possible.
Marr said Collegiate captain Angus Dinwiddie did his best to manipulate the attack to get Fraser off strike so his team could bowl at the "old men".
"It only takes one guy. We missed an opportunity against [Fraser] and that's all it takes."
Kelt took 3-17 from his eight overs in an MVP performance.
It was the start of a busy Labour Weekend for Collegiate, who are currently playing a two-day game against New Plymouth Boys High School.
Next weekend, they will take on St Johns Tech coming off the bye, while United will meet Marist.
Both the undefeated sides will be hoping the match can be played on Victoria Park's Tasman Tanning No1, which was looking good during the Central District Hinds vs Wellington Blaze games this weekend.
United vs Saracens had been scheduled for Tasman Tanning No3, before overnight rain on Saturday saw the match moved down to the artificial wickets.
Results
Marton 149 (J Trillo 98, S Oliver 18, B Walker 4-9, S Badger 2-30, L Wilsher 2-38) lost to United 151-2 (T Lance 74, A Bostock 25, G Smith 21, M Thomson 2-19) by eight wickets.
Wanganui Collegiate 147-7 (B Kelt 58, N O'Leary 21, G Hamilton 2-14, J McIlraith 2-27, M Gill 2-31) lost to Marist 149-7 (M Fraser 72no, J McIlraith 31, B Kelt 3-17, C O'Leary 2-30) by three wickets.
