Three key partnerships carried the Tech innings.
Kane Watkin and Gill pushed Tech through to 101 before Watkin and Ross Kinnerley fell in quick succession leaving Tech 124-5.
Gill was then joined by Jess Watkin and the pair lifted the run rate in their 55-run partnership. Soon after Watkin departed for 21 and when Gill reached his century off 81 balls in the 30th over with Tech at 193-6.
A 45-run eighth wicket partnership with Peter Czerwonka helped Gill close in on 150 which he brought up after a being dropped on 149.
In reply Marist's innings never got going enough to chase down Tech's big total with wickets falling regularly as they were dismissed for 143 in 37 overs.
Kent Darlington and Nicholas O'Leary were the pick the Marist batsmen, top-scoring with 25 while Thomas Redpath added 21 batting at 10.
Tech's Jess Watkin picked up 4-12 in just five and a half overs.
In the other match involving Wanganui sides, Matt Burke Engineering Marton Saracens edged Property Brokers United in final-over thriller at Centennial Park in Marton.
United needed nine runs off the final over with one wicket in hand and top-scorer Greg Smith, who had just brought up a half-century, was still in.
Smith scored 2 off the first ball but was bowled by Daniel Ford the next.
Batting first Marton put on 150 after battling through to 59-2 at just over two runs an over. Craig Clare top-scored with 36 in a top order which all hit double figures but failed to kick on.
Chris Sharrock and Robbie Power snared three wickets each for United.
United's reply was just as slow but Smith's half century and a 49-run partnership with Sharrock had the visitors in a winning position.
Meanwhile, the four Horowhenua-Kapiti Clubs postponed their matches until yesterday. Levin Old Boys were playing Weraroa and Paraparaumu were taking on Kapiti Old Boys.
The Coastal Challenge takes a break next week for Hawke Cup representative fixtures before all Wanganui clubs travel south to play Horowhenua-Kapiti sides the following weekend.