Seaham Park produced an outstanding all-round display to hand morning leaders Crook their first defeat of the season in Division One.
The unbeaten visitors went into the game with eight wins from 10 games, but Park turned on the style to secure a fine 116-run success.
The Seaham side were put in to bat, and made the most of their opportunity to post 217-7 in 50 overs.
Opener Martin Stephenson hit 33 off 71 balls, with five fours, putting on 52 for the second wicket with Virat Singh, whose 77 (off 90 balls) featured 10 boundaries.
Shoaib Akhtar added 25 (with three sixes and a four), Mark Race 32 not out, with four fours, and Jack Lacey 15. William Angus (2-41), Daniel Doram (2-45) and Jamie Wills (2-35) were the pick of Crook’s bowlers.
The home attack then took command to ease to a big victory as Crook were dismissed for 101 in 40 overs.
The visitors put 52 on for the first wicket, with Andrew Pratt scoring 44, but they collapsed from that point as Park’s bowlers turned on the style, with Singh taking 3-10 and Dave Gilbert 3-21. Jack Lacey took 2-33, while John Sample’s four overs produced 2-2.
Easington capitalised on Crook’s setback to move into pole position, following a comfortable six-wicket win at Bill Quay.
Omar Shahid grabbed 4-15 and Duvindu Tillakaratne took 3-12 as Easington dismissed their Tyneside hosts for 93, with Alan Mustard (32) top-scoring. Skipper Gary Ward (2-25) and Jordan Wilson (1-41) weighed in with late wickets.
David Tarn hit 30 to ease Easington home to their ninth victory in 11 league matches so far, with Ryan Higgins adding 22 and Ward 14, while on-form Robbie Atherton hit three boundaries and a huge six in 20 not out to steer his team over the line.
Van Blerk grabbed 3-40 in vain for Quay.
Durham City picked up only their third victory to ease their relegation worries, finishing off Tudhoe to win by just six runs in a nail-biting, close-fought battle.
Opener Cameron Fyfe was the star of the show for City, making more than half their runs with 12 fours and a six in an 85-ball 62. Alex Cook added 15 and Callum Steel 13, but the Green Lane were all out for 121 in 40.5 overs.
Daniel Brown plundered 4-22, while Roshan Jayatissa took 3-33.
Tudhoe looked on course for victory until a late rush of wickets saw them sent packing for 115, seven short of victory. Daniel Thexton top-scored with 35, backed by Abhiram Joshi (26) and Ian Grainger (22).
Nick Howe was outstanding with the ball, grabbing 6-24 in 8.5 overs, while Paul Moralee took 3-18 in 12 overs.
Esh Winning moved up to third, following a three-wicket win at Horden, who batted first and made 173 all out.
Adam Dixon top-scored with 41 for lowly Horden, while Wayne Birks made 24 before being stumped after misjudging a slow delivery from Jamie Robinson.
Only Paul Dixon, with an unbeaten 26, and 19 from Adam Scott offered much support.
Robinson took 3-43, with Paul Chivers, Eddie Watson and Daniel Wilkinson each taking two wickets.
Esh then had Stu Hall (31) and Gary Henderson (55) to thanks for the win as they guided their team home, despite Adam Dixon snatching an impressive haul of 5-50. JP Meade took 2-31.
Philadelphia could only muster 126 all out away as they succumbed to defeat at Marsden.
Gary Braithwaite was Phil’s top runmaker with 29, while Colin and Chris Mann each took two wickets and Steven Neilson returned 4-24.
Phili made life difficult for the home side in their reply, as Reece Wood, with 3-44, and Stevie Wright (4-18) had them struggling, but Chris Mann (39) and Matthew Evans (27) guided them home by just one wicket.
Mainsforth drew at home to Whiteleas and Harton, after they had posted 180-8, with Tom Orton scoring 31, Adam Thompson 44 and John Cavanagh 32.
Hafiz Aleem and Ray McRae each took three wickets on the bowling front.
McRae then made 42 with the bat, but Leas had to hang perilously on for the draw, finishing on 167-9, with Lewis Jewett taking 3-26.