Ouseburn climbed above Birstwith and into pole position in Theakston Nidderdale Division One after emerging victorious from Saturday’s top-of-the-table clash between the title rivals.
The defending champions have now won seven games on the bounce and inflicted a second successive defeat on the former leaders, who were unbeaten in 2017 until last weekend.
Some fine bowling from Tom Parker (4-37) and Chris Morrison (3-35) helped restrict Birstwith to 179/9 from their 45 overs, Tom Croston top-scoring with 34.
A knock of 49 from opener Sam Parker, plus 48 from Jamie Bryant then set Ouseburn on their way before Adam Fisher (32 not out) got them over the line at 180/5.
Craig Robinson took 2-40, but his efforts proved to be in vain.
Helperby also leapfrogged Birstwith in the league standings, moving up to second spot courtesy of a narrow victory over Hampsthwaite.
Opener Luis Rees-Hughes picked up where he left up last time out, following up his half-century against Birstwith with an innings of 72 not out.
Dan Marston also contributed 47 in Helperby’s 207/6, George Beeley grabbing three wickets.
Max Beeley hit 70 in reply as the contest went down to the final over, however Hampsthwaite finished up six runs shy of their target on 201/8.
Alne’s Rich Henley came agonisingly close to making a century against West Tanfield, but his knock of 98 not out laid the foundations for the men from the Magic Circle recording a first triumph of the campaign.
Henley’s runs and an unbeaten 80 from Alastair Jackson saw them compile 261/5, Josh Barrett claiming 4-30.
Tanfield were then blown away with just 108 on the board in reply, Cameron Spence (3-24) and Toby Stirke (3-32) doing the damage for bottom-of-the-table Alne.
Knaresborough Forest chalked up back-to-back wins when they got the better of Goldsborough.
Aaron Brunner continued his good form with the willow in hand, striking 63 at the top of the order before Ben Challis weighed in with 59 to guide Forest to 239/9.
Jarrod McPhee (4-61) and David James (4-85) led the Goldsborough attack well, but their batsmen were ultimately unable to chase down the total they needed for victory.
Gavin Hodson (43) and McPhee (36) both made starts, however 4-34 from Joel Ainsley saw the home team dismissed for 170.
James Townsend smashed an unbeaten ton to help fourth-placed Burton Leonard ease past struggling Spofforth on home soil.
Devon Nightingale stuck 55 and James Roberts made 34 in the visitors’ 183/6, Iain Barker the pick of the Burton attack with 2-38.
Townsend then hit 16 fours and a pair of sixes in a 93-ball innings of 103 not out, while Neil Blaken added 55 as the hosts cruised to 186/2 with almost 12 overs to spare.
Masham recorded an eight-wicket success at home to Darley.
Brad Stephens hit 71 in the away team’s 172 all out as Dan Woolston snapped up 3-37.
Captain Phil Newton (61) and fellow opener Andrew Smith (55) then led Masham to maximum points at 174/2.
Dacre Banks took over at the Division Two summit after they beat Scotton and early season pacesetters Studley Royal went down at Blubberhouses.
Skipper Sam Halliday’s 36 was the best that Scotton had to offer in their total of 163/8, Steve Ellison, Mitchell Hearn and Paul Ellison taking a pair of wickets apiece.
Hearn looked set to complete a fabulous afternoon’s work with a century, but Banks made it to 169/6 with him just short of a milestone score on 96 not out.
Studley Royal posted 172/8 batting first against Blubberhouses, but a virtuoso allround display from Aamir Rehman condemned them to defeat.
Lewis Day made 38 for Royal but Rehman claimed 4-42 with the ball.
The same player then struck 85 not out as Blubberhouses took just 28.5 overs to knock off the runs needed for a five-point haul that moves them above their opponents and into second spot.
Markington had little trouble in getting past Bishop Thornton, eventually running out winners by a seven-wicket margin.
A five-wicket haul for Cecil Gordon and four scalps for Graham Bassitt sent Thornton on their way back to the pavilion with just 129 to their name, Ed Paxton (31) their most successful batsman.
Peter Johnson’s 49 not out and 46 from the bat of Dave Askew then sealed the home side’s success for the loss of just three wickets.
Raskelf secured a fourth victory of the campaign and put some distance between themselves and the relegation zone when they shocked Wath & Melmerby.
Mitchell Cross managed 42, but that was as good as it got for the visitors as 4-32 from Barry Petty helped restrict them to 142/9.
Angus Taylor’s innings of 49 not out, plus 29 not out from Bradley Clark then eased Petty’s troops to 143/3.
Struggling Ripley compiled a total of 210 all out at Burnt Yates, but it wasn’t enough to save them from defeat in a close contest.
Andrew Carrick (71) was the away side’s leading man, Michael Sacchetta adding 41, while Steve Light returned excellent figures of 5-47.
Jason Chyer’s 73 and an innings of 45 from Russell Dodson then took Burnt Yates to 211/7 in response, the hosts reaching their target with two overs in hand despite a trio of wickets each for Matt Roberts and Grant Stancombe.
Pateley Bridge heaped more misery on rock-bottom Newby Hall when they bowled them out for just 87 before quickly chasing down their victory target.
Alex Wilson’s 31 was the only highlight of Hall’s innings as Tom Fryer wreaked havoc with a spell of 5-28, before Tom Clements cleaned up the tail with 3-7.
Joe Preece then struck 41 as the Badgers wrapped things up at 88/3 in 22.1 overs, Nitin Mukerji bagging three wickets.
On Sunday, Helperby knocked 2016 Atkinson Swires Senior Knockout Cup finalists Darley out of this year’s competition at the quarter-final stage.
Darley were dismissed for 186, Rob Best making 42 as Luis Rees-Hughes took 3-40, before Dylan Steyn hit 48 as Matt Cavanagh’s men made it to 190/3.
Helperby will meet Birstwith in the last four after they overcame Blubberhouses in a run-fest.
Jonny Millward’s 96 saw Birstwith to 329/8 and although Bash Khan struck 50 in reply, the second division outfit were all out for 245.
Chasing Masham’s 203/9, Ouseburn were skittled for just 74 as Nathan Kleinig (4-6) ran riot having earlier smashed 91 not out.
A knock of 73 not out from Aaron Brunner guided Knaresborough Forest (134/6) past Studley Royal (132 all out).