They are now up to ninth after a superb century from skipper Alexei Kervezee and another high-quality innings from Billy Cox.
Halesowen batted first and got off to a steady start before a third-wicket stand of 129 between Cox and Kervezee.
When Cox was dismissed for 87, Kervezee carried on and hit an unbeaten 122 from 107 balls – with 14 fours and three sixes along the way.
Simon Gregory added a welcome 34 runs from 26 deliveries to help Halesowen finish 299-5.
Nick Hammond’s classy 100 from 131 saw visitors Ombersley claim a losing draw as they ended 186-8.
Smethwick strengthened their grip on top spot in Premier One as they beat Kenilworth Wardens by 28 runs. The table-toppers declared at 324-3 and nearly saw that decision backfire on them.
Smethwick had openers Qamar Khan (68) and Rajpal Beniwal (34) lay a solid foundation before a third-wicket stand of 190 between Roshan Venkataraman (124 not out) and Bilal Shafayat (94).
That saw them declare with two overs to spare, and it looked to be a questionable call as Jamie Harrison thumped 122. Manraj Johal and Yasir Ali, though, wrestled the game back into Smethwick’s favour.
Wardens reached 243-2 in the 38th over but a superb second spell from Warwickshire seamer Johal (5-52) was well supported by Ali (3 for 56) as Smethwick celebrated yet another victory.
Kidderminster triumphed by nine wickets against Berkswell on a fine day with the bat and the ball.
Kidderminster’s Liam Weston and Chris Steele took eight wickets between them as reigning champions Berkswell were 182 all out in the 50th over. All three batters who came to the wicket then registered half-centuries. Andrew Kimberlin and Vikai Kelley were both unbeaten on 57 after Neil Pinner was the only man out for 53.
In Premier Two, league leaders Wolverhampton won by four wickets at Walsall.
Ramanjot Jaswal (65) and Charlie Home (69) were the difference-makers as Wolverhampton successfully chased down Walsall’s 219-6.
West Bromwich Dartmouth beat Bridgnorth by seven wickets, with Kobe Herft managing an unbeaten 76 after also taking three wickets. Himley grabbed a losing draw in a rain-affected clash with Dorridge. Brinder Phagura’s unbeaten 64 helped Lichfield win by three wickets at Harborne.