Opening bowler Harpreet Binning (2-40) had early success before the rest of the top order, Locky Spring (24), Keegan Maclachlan (17), Jamie Marshall (25) and Kelsey Fahey (38), all got starts – Fahey stroking six boundaries and a six in the 35 balls he faced.
Nonetheless, bowlers Simon Badger (3-31), Brendon Walker (3-36) and Martin Pennefather (2-40) all caught up with them to have the home side in trouble at 163-8.
However, tail-ender Jaedyn Dawson struck back with 33 not out in 23 balls to give his side a challenging total with United's overs reduced by the rain.
United lost their veteran openers early until a promoted Walker hit 25, and then it looked like the visitors would stay on track as Zeb Small (33) and Badger (53) played a steady partnership.
Wicketkeeper Zak Guiniven went on the attack with 36 from 22 balls, including four boundaries and two sixes, and at 198-5 United were nearly home.
However, Guiniven's dismissal to Caleb O'Connell (3-24) triggered a collapse under pressure as the last five United wickets fell for 17 runs, two of them being run-outs.
Weraroa's win means their trip to Tasman Tanning Park this Saturday to play Marist will be a virtual quarterfinal.
In the other games, Kāpiti Old Boys extinguished Burger King Red Star's semifinal hopes by travelling to Masterton to administer a heavy 77 run defeat, while Levin Old Boys made a big statement with their rain-reduced four wicket victory over Paraparaumu Medical Centre CC to go top of the table.
P2 40 competition
The latest round of the P2 40 saw Wanganui Renegades stay alive to keep the pressure on table leaders Tech Old Boys by beating rivals Treadwell Gordon United 2nd XI by seven wickets.
In the battle of second vs third on the table, Renegades bowled United out for just 90 in 31 overs, and slogged their way to the winning runs in just 13 overs.
Matt Burke Engineering Marton Saracens moved at least temporarily up into second place with a comfortable six-wicket win over Wanganui United 3rds at Centennial Park.
Whanganui Collegiate 2nd XI picked up their second win on the trot with a big 97-run victory over Kaitoke Knight Riders.
Three of the student batsmen scored half-centuries in their innings of 242, and although Kaitoke got away to a quick reply, they lost wickets and then couldn't keep up with the run rate.
Wicket Warriors Whanganui spoiled Old Timers' Day for the Marist Bs with a very narrow victory.
Results for March 5
Coastal Challenge Cup
Wanganui Vet Services Marist bt United CC by default.
Weraroa CC 219 (K Fahey 38, J Dawson 33no, J Marshall 25, L Spring 24; S Badger 3-31, B Walker 3-36, H Binning 2-40, M Pennefather 2-40) bt Property Brokers United 215 (S Badger 53, Z Guiniven 36, Z Small 33, B Walker 25; C O'Connell 3-24, C Trask 2-28) by four runs.
Kāpiti Old Boys 192 (R Hickey 56, M Harrison 45; G Deans 3-35, A Jaspers 2-22, P Wootton 2-28, O Patel 2-46) bt Burger King Red Star 115 (J Anderson 35, J Wylie 22; M Harrison 3-10, C Andrews 3-21, Z Benton 3-30).
Paraparaumu Medical Centre CC 186 (S O'Brien 48, N Harvey 48, D Reder 29, A Kumar 22; J Parker 3-22, D Sanson 3-28, A Simpson 2-16) lost to Levin Old Boys 179-6 (M Good 68no, B Te Tomo 43, A Simpson 36; D McNamara 3-53, S Windle 2-32) by four wickets under D/L method.
P240
Wicket Warriors Whanganui 86-9 bt Marist Bs 83.
Whanganui Collegiate 2nd XI 242-4 (L Bullock 58, G Ormsby 57, M Peacock 51, M McVerry 26, S Abernethy 26no; M Slade 2-34) bt Kaitoke Knight Riders 145 (R Bellis 29, Z Payne-Potaka 24; H McVerry 4-18, T Ripe 2-37) by 97 runs.
Treadwell Gordon United 2nd XI 90 (A Heap 3-6, M Deighton 3-12, J Donaldson 2-25) lost to Wanganui Renegades 91-3 (J Trillo 29, A Heap 28no, J Deighton 20) by seven wickets.
Wanganui United 3rds 138 lost to Matt Burke Engineering Marton Saracens 140-4 by six wickets.
Bye: Tech Old Boys