Harris chipped in with an enormous 169 in an empathic triumph at Harborne, making it three victories from as many games in Premier Division Two.
A wonderful third wicket stand of 191 by Harris and Alex Hinkley (80) saw Halesowen to 332 for six in 50 overs.
The former faced 144 balls and struck 25 fours and four sixes, with the also-impressive Hinkley hitting nine fours and two sixes from 71 balls.
Bottom club Harborne barely got going in their response and after slumping to 19 for four, they were eventually all out for 76. Eddie Rhodes (six for 30) and James Rudge (three for 42) bowled unchanged throughout the innings, which was done in 19 overs.
Himley got off the mark as they cruised to an eight-wicket win at Oswestry.
Dan Vernon, with four for 22, took crucial wickets as the hosts were all out for 171.
Bilal Hussain's 46 and an unbeaten 43 from Callum Lea then helped Himley successfully chase down that target.
Wolverhampton remain winless despite a spirited late effort at Barnards Green.
Oliver Rogoff (94) inspired the home side to 264 for eight and, in response, Wolverhampton got off to the worst of starts as they collapsed to seven for three.
A sixth wicket stand of 129 between Charlie Home (94) and Joe Stanley (70), though, added some respectability as they ended up finishing 67 runs short.
Pelsall, meanwhile, agonisingly missed out on a first victory of the season at Kenilworth Wardens.
After being pipped by two runs at Dorridge, it was a one-run defeat this time around.
Wardens were invited to bat first after losing the toss and it took a composed century from skipper Harry Johnson (107) to take them to 240 all out, with Todd Henderson returning figures of three for 32 for Pelsall.
With Andrew Bentley (51) and Tom Wright (48) to the fore, Pelsall lost their eighth wicket off the last ball of the innings on 239 when Wright was run out.
In Premier Division One, Smethwick chalked up their first win of the campaign with a tense one-wicket success at Knowle & Dorridge.
Chasing down 208, Smethwick owed much to Qamar Khan's 85 before the last wicket pair of Naseer Ahmed and Karmajot Singh clinched it.
On a fine surface at Shifnal, Walsall’s total of 239 for six from 50 overs proved too light as the hosts sealed a seven-wicket win.
Kidderminster lost by three wickets at table-toppers Berkswell. Debutant Adam Hose top scored with 88.
Finally on Saturday, West Bromwich Dartmouth lost by 110 runs to Barnt Green – and they were then beaten by the same team in the Graham Williamson Trophy on Sunday.
Looking to reach the Trophy final, Dartmouth won the toss, chose to bat and finished on 161 for nine from 40 overs – Kabir Ali coming up with 32.
Barnt Green, though, won by six wickets thanks in large part to half-centuries from Jacques Banton (58) and Amrinder Brar (50).