"A bit lucky, although it was hard to bowl out there," Walker said of his first century for the club.
Robbie Power chipped in with 44 as United amassed an intimidating 333-6 from their innings. Tech were soon all at sea at 1-2 in the second over as both the Lock's - Tyler and captain Dominic - fell to accurate deliveries from Ryan Slight and Ritesh Verma.
That brought on the remaining hope in Nick Harding, who knows only one way to play and went on the attack - hitting Verma back over his head on both sides of the wicket in consecutive deliveries.
However, the veteran Verma was up to the challenge and got the edge into Sharrock's gloves off the very next ball, with Harding gone for 37 off 22 balls and his team in the cart at 60-4.
United went aggressive by putting in six slips and wickets would fall steadily, although there was a wag in the Tech tail as No10 batsman Devon Purvis put up a fighting 51, including four sixes, until Lance grabbed a caught and bowled chance to wrap things up.
Lance would finish with 3-41 from 9.4 overs while Verma took 3-46 from his six, the figures more impressive when the scrap with Harding is removed.
Across the way, Marton captain Dom Rayner had to shrug when he heard Walker had pipped him for the best score of the day at that point, as his 104 carried Matt Burke Engineering Saracens to a defendable 235-7 against Marist.
After struggling last summer with the bat, Rayner's century followed up 40 the previous weekend and his team will definitely need him to keep delivering, as the best support came from Scott Oliver (25) and Hamish Harding (31).
"I usually start the season not too bad, so hopefully it carries on," he said.
Rayner's bread-and-butter was scoring off short deliveries on the offside, giving away one sharp chance from the 116 balls he faced, while hitting eight boundaries and one sixer.
The Marton skipper had to tip his hat to Marist's Craig Thorpe, who despite bowling into the wind would send down 45 dot balls amongst measly figures of 1-25 from his 10 overs.
"He did really well ... the wind was holding [the ball] up, hard to get away," said Rayner.
Meanwhile, Marist's John McIlraith continued his profitable returns against Saracens with both bat and ball, helping set up a five wicket win.
Not usually bowling a full complement of overs unless the team is short, McIlraith got the prized wicket of Rayner amongst his 3-34, although he acknowledged having the breeze behind him assisted.
He then went out to get the day's larger score, making 108 as part of a 126-run opening stand with Sam O'Leary (41), before carrying on with Chris Stewart (42 not out).
McIlraith struck 12 boundaries and three sixes in his innings, and although Marist got a couple of speed wobbles after his dismissal by Dan Ford - with the middle order of Mark Fraser, Thorpe and Shaun Jones departing - Stewart tidied things up with Cameron Beard in the 45th over.
Both Walker and Rayner felt that while getting a century was great, the true test of batsmanship will come when the Wanganui teams can get off the artificial turf and back on to Victoria Park and Marton's Centennial Park pitches.
However, it has been a similar story for the Horowhenua-Kapiti teams to start their campaign, with the regular wickets not quite ready.
Saturday's results leave United on top of the Coastal Challenge Cup table, ahead of also undefeated Paraparaumu CC, who had a three wicket win over Kapiti Old Boys after bowling them out for 94.
Levin Old Boys beat Wereroa CC by five wickets, making 229-5 when chasing 227-3.
This coming Saturday, Tech have a home game with Wereroa, while Marton face Paraparaumu in a game which may be moved away from Centennial, while Marist and United travel to Donnelly Park to meet Levin and Kapiti respectively.
"It will breathe a bit of life into it," said Walker about having new opponents.
"It was starting to stagnate a bit, so it will be good to get away [for games]."
Results, October 17
United 333-6 (B Walker 105, G Smith 81, R Power 44, K Watkin 2-92, N Harding 1-36) bt Tech 187 (D Purvis 51, N Harding 37, T Lance 3-41, R Verma 3-46, R Slight 2-24).
Marton 235-7 (D Rayner 104, H Harding 31, J McIlraith 3-34, S O'Leary 2-24, C Thorpe 1-25) lost to Marist 236-5 (J McIlraith 108, C Stewart 42no, S O'Leary 41, D Ford 2-47).
MVP
Saracens vs Marist (Umpires Neil Kirkwood and Lindsay Hobbs) - John McIlraith (Marist) 3; Dominic Rayner (Saracens) 2; Sam O'Leary (Marist) 1.
Tech vs United (Umpires Martin Inness and Ben Lourie) - Brendan Walker (United) 3; Greg Smith (United) 2; Devon Purvis (Tech) 1.
