Tom Chippendale captured a stunning six wickets in eight balls as Bradford Premier defending champions Hanging Heaton crushed Lightcliffe.
Their batting had already put down a marker, building on a 126-run stand between Gary Fellows (80) and Joe Fraser (63) to race to 357-6, with half-centuries for Callum Geldart, Ben Kohler-Cadmore and David Stiff.
Chippendale then struck, with three in five balls followed by a hat-trick in his next over as Lightcliffe crashed out for 32.
That moved Hanging Heaton to within six points of second-placed Pudsey St Lawrence, who lost by 22 runs to Methley.
David Shuffe (53) and Grant Soames (44) helped Methley to 231-9 and Saints’ hopes of overhauling them ended when Charlie Parker (27) was run out.
Steve Bullen (88) and Joe Bedford (63no) put on 162 for the sixth wicket as leaders New Farnley recovered from 38-5 to 231-8, and a 6-43 spell from David McCallum clinched a comfortable win over Bradford & Bingley.
Despite a 6-55 return from Josh Thurwell, Farsley set 268-8 with Dan Hodgson (100) and Patrick Kruger (68) putting on 108. Kruger took 4-18 as Cleckheaton were dismissed for 132.
Yasir Ali (74no) and Shoukat Ali (52) led the way as Scholes overtook East Bierley’s 247-9 in which Shabir Rashid (60) and Rizwan Ali (76) starred.
Tim Jackson (72) and Ishfaq Ahad (63) set the platform of Woodlands’ 272-5 and Kez Ahmed (5-56) led them to a 22-run win at Townville.
Wickersley inflicted a first defeat on Yorkshire South leaders Sheffield Collegiate, Thomas Knight (95) and Cameron Gordon (6-44) heading the charge.
That allowed Wakefield Thornes to take over top spot after they edged past Whitley Hall by three wickets.
For the second week in a row Harpeet Singh was involved in a record partnership. He scored 154 and put on 190 for the third wicket with Ben Fosdick (89) in Barnsley’s 336-6 and even though Johannes Bothma (54no) and Rob Ward (40no) equalled the eighth-wicket record, Aston Hall came up 97 runs short.
Alex Grimes (44) starred as bottom side Appleby Frodingham beat Whiston by 44 runs while James Stuart (7-41) and Ali Waqas (61no) helped Doncaster beat Cleethorpes by seven wickets.
Nick Dymock (92) top scored in Hallam’s 314-4 and even though Sam Drury smashed 97 in 60 balls, Treeton lost by 54 runs.
With Daniel Woods taking 5-25 Scarborough just missed out on beating Yorkshire North leaders York, who needed a seventh-wicket century stand from Tom Spearman (56) and Tom Brooks (58) to reach 211-8.
Adam Fisher (140) and Dulash Udayanga (108) put on 215 as Sheriff Hutton Bridge crushed Acomb by 137 runs despite Matthew Dale’s 70, Udayanga taking 4-30.
Josh Atkinson (102) helped Harrogate recover from 59-5 to pass Driffield Town’s 205-9, while Sam Grant (5-40) had Castleford on the ropes until Connor Hyde (42no) and Edward Cole (37no) edged them past Clifton’s 120.
George Hill (122) and Tim Loten (59) helped Yorkshire Academy to 265-5 and victory over Woodhouse Grange for whom Andrew Bilton made 95.
Navin Kavikara (5-48) restricted Stamford Bridge to 207 with Dominic Rhodes (52) and Ryan McKendry (67) top scoring but Sessay fell 36 short despite the efforts of Jacob Spencer (77).
Abdul Wahid (71) and Sam Mills (5-37) inspired Golcar to pull off a shock win over second-placed Honley and move off the bottom of Huddersfield Premier.
A six from Terence Jones (31no) clinched Mirfield Parish Cavaliers’ win over fellow strugglers Shelley.
Nathan Rabnott smashed an unbeaten 145 as Moorlands won a high-scoring match against Cawthorne while Richard Marshall (132no) and Ben Raven-Hill (74) helped Thongsbridge pass Kirkburton’s 236-7.
Alex Morrell (98) starred as Beckwithshaw beat Pool by four wickets to climb off the bottom of the Aire Wharfe.
Otley beat crushed fourth-placed North Leeds after Stephen Brown (79) and David Hester (100no) set a 288-8 target.
Daniel Revis followed up a 4-36 haul with an unbeaten 148 to see Burley pass Bilton’s 255-9.