Tim Jackson led the way with 71 as Woodlands raced to 223-6 in a match reduced to 40 overs.
Despite 55 from opener Simon Lambert, Undercliffe were dismissed for 152 and Woodlands were Bradford League champions for the first time since 2012.
Khalil Khan followed up a 3-8 spell with 70 to give Wrenthorpe victory at Lightcliffe in the battle of the bottom two.
While that raises Wrenthorpe’s hopes of escaping the drop, they remain in the bottom two because the side immediately above them, Methley, also won. Jared Warner (4-36) helped restrict Farsley to 161-8 and Jordan Laban (53) set the foundations for the win.
Alex Lilley (55) and Charlie Parker (43no) were the leading scorers in New Farnley’s 193-6 and with Parker taking 5-30, Cleckheaton could only make 154-9, Toby Thorpe unbeaten on 63.
There was a thrilling finish at Pudsey St Lawrence where Imran Rafique took 5-27 as Harry Cullingford helped the home side set a target of 176-9.
Townville wickets fell steadily but an eighth-wicket stand of 78 between Harry Warwick (69no) and Alexander Page (33) helped the visitors grab victory with one wicket and one ball to spare.
Karl Carver’s season-best 6-38 haul set Sheriff Hutton Bridge on their way to victory at Harrogate and with Dulash Udayanga (41) and Matthew Fisher (44no) having set the platform, Carver hit the run that secured the Yorkshire North title.
Relegation for Beverley Town was confirmed after David Taylor (52) and Matthew Montgomery (122) put on 102 in Clifton Alliance’s 249-6 and Sam Grant (5-34) helped dismiss Town for 122.
Sessay were also relegated despite Navin Kavikara (6-24) restricting Stamford Bridge to 163, in which Kyle Waite hit a half-century. Sessay fell 48 runs short, Dominic Rhodes taking 4-15.
Luke Kilby took 6-59 as Woodhouse Grange made 152 and a last-wicket stand of 47 between David Brent and Jonathan Anderson grabbed a win for Dunnington.
Scarborough captain Sam Drury hit 111 and took 5-39 as his side pipped Castleford by seven runs, while Finlay Bean’s 74 not out was the highlight of Yorkshire Academy’s 171-7 but York still won, James Billington (44) helping them past a revised target.
Stephen Foster (85) and Ben Birtles (53no) were the main contributors to Treeton’s 218-5 before Foster (5-17) and Will Street (4-2) skittled Barnsley for 52.
With Aamir Jamal (5-53) and Curtis Free (4-41) restricting Wickerlsey to 169, Bilal Anjam (64no) and Joe Gallagher (40no) eased Doncaster Town to the Yorkshire South title just three years after suffering relegation.
Andre Bradford (47no) and Jack Snelling (40no) clinched the win that almost completes long-time strugglers Hallam’s great relegation escape while confirming Aston Hall will go down.
Even though Saeed Anwar and Muhammed Ilyas each picked up four wickets, a half-century from Callum Carter helped Cleethorpes to 136 and a four-run win over Elsecar that boosted their hopes of escaping the drop.
Neil Longhurst (52) and Jack Wood (5-44) starred as Whitley Hall overcame Sheffield Collegiate while Wakefield Thornes won by seven wickets at Tickhill after Satyajeet Bachhav (4-29) restricted the hosts to 121.
Stephen Brown took 4-34 and top-scored with 37 as Otley moved closer to retaining the Aire Wharfe title with a win that sent Pool into the bottom two.
The relegation spots are wide open after Mark Dixon (4-6) helped to skittle Bilton for 44 to set up victory for bottom club Adel, and Toby Jacklin (4-24) and Charlie Swallow (3-25) dismissed Ilkley for 94 to send Collingham from 11th to seventh in the table.
Rawdon are in the mix after Ricky Palacio took 6-27 to clinch victory for Addingham.
In Division Two, Saltaire beat New Rover to secure back-to-back promotions and the individual performance of the day was that of Tong Park Esholt’s Mahir Ali whose 10.4 over spell of 9-10 saw Ben Rhydding crash out for 39.