Experienced opener Toby Doyle smashed a quick-fire 32 before the Sefton fielding unit slowly squeezed control back.
Jeff Jones and Nigel Granger dried up the runs while Matt Laffey chipped out three wickets to help restrict the combined side to 133/9 in their 20 overs. Will Macfarlane's fine 40 off 34 balls helping lift them to some respectability.
Sefton took advantage of an early dropped catch and jumped on the accelerator, with openers Arora (56 runs off 36 balls) and Mackenzie Smith (64 off 37) knocking off the runs in just 12 overs to secure a dominant 10-wicket win.
A brilliant innings by former Black Cap and Canterbury stalwart Shanan Stewart wasn't enough to save a short-handed Southbrook from embarrassment on Saturday.
The 'Brook batted first at Weedons Domain and Stewart's 88 off 68 balls – well supported by Hayden Thornley's 39 – helped guide them to a decent 145/5.
Limited bowling stocks hurt Southbrook's chances of defending the total and Weedons' openers Brad Nightingale and Todd Inness took full advantage.
The pair chased down the total easily, with 4.3 overs to spare, and without losing a wicket – Inness finishing on a superb unbeaten 72 and Nightingale 57 not out.
Cheviot Magpies are also unbeaten on three wins after two victories on Saturday, beating Ohoka by 38 runs and Lincoln narrowly by 13 runs. Ryan Ellis starred with the bat in both games for Cheviot making 44 and then 93.
Oxford-Rangiora beat Lincoln handily while Ohoka came back from their first loss of the day to beat one-day competition leaders Darfield and keep them winless in the shortest format of the game.
Short scorecard:
• Leeston-Southbridge 133/9 (W Macfarlane 40, T Doyle 32; M Laffey 3/30, M Campbell 2/23, C Ward 2/30)
Lost to Sefton 136/0 (M Smith 64no, A Arora 56no).
• Southbrook 145/5 (S Stewart 88, H Thornley 39; A Deb 2/22, C Robson 2/29)
Lost to Weedons 148/0 (T Inness 72no, B Nightingale 57no).
• Cheviot 137/4 (R Ellis 44, H Fitzpatrick 27, A Redfern 22, H Darling 22no)
Beat Ohoka 99 (N Burnett 33, T Beale 20; S Burnett 3/9, C Cameron 2/16, T Fitzpatrick 2/29).
• Lincoln 136/7 (T Holland 64; T Dwyer 3/26, J Waghorn 2/19)
Lost to Oxford-Rangiora (J Waghorn 44, C Scott 36no).
• Cheviot 187/3 (R Ellis 93, A Redfern 36, T Whelan 29, H Fitzpatrick 22no)
Beat Lincoln 174/5 (T Holland 84, T Cross 35, L Robinson 31no; H Darling 2/33).
• Darfield 94 (A Bell 24, A Collins 20; Nathan Court 5/4, J Belton 2/16)
Lost to Ohoka 106/0 (A Hamilton 54no, D Lyons 50no).