Carl Wilson (36) and Peter Morgan (34) helped previously unbeaten Bourne to 128 before they were dismissed, Jamar Ifill (4-29) and Thomas Giles (3-21) doing most of the damage.
Ifill added 69 runs as the hosts reached 129 for 6 to conclude a four-wicket victory in the 24th over.Sleaford claimed maximum points at Louth with an eight-wicket success.
The hosts were dismissed for 108 with the title-chasers responding with 110 for 2 after 16 overs.
Grantham, 17 points behind Sleaford in third, lost by 59 runs at Spalding.
Openers Mitch Freeman (72) and Jon Manton (65) inspired the home side to 249 for, Grantham dismissed for 190 with Bilal Hussain (59) and Aqib Afzaal (57) top scoring.
Muhammad Kaleem took three Spalding wickets while Brandon Andrews (four) and Freeman (three) bowled well for the hosts.
Fourth-placed Lindum also lost this weekend after fifth-place Woodhall Spa left with a 69-run win.
Matt Carter's 66 and a half century from Ross Dixon guided the Spa men to 225 before the side were dimsissed
Andy Harris took three Woodhall wickets.
In response, Alex King and Nick Bennett also took three apiece as Lindum were gone for 156, Patrick Barker hitting 66 of those runs.
Market Deeping won by 95 runs at Skegness, Zeeshan Manzoor's 62 guiding them to 176, Jamie Epton and Vineeth Venugopalan both taking three wickets each.
Skegness were all out for 81.
Hayatullah Niazi (6-23) did most of the damage, the seasiders' top score coming from George Gregory (21).
Bracebridge Heath won by six wickets as they entertained Nettleham.
Mitchell Slattery and Thomas lea both struck 37 runs before Nettleham were out for 169.
Kit Spence (45), Sam Mason (40) and Taylor Fell (30) helped Bracebridge post 171 for 4.
James Holden (4-27) was the pick of the Bracebridge bowlers.
Lincs ECB Premier
Scunthorpe Town 129-6, Bourne 128 all out; Bracebridge Heath 171-4, Nettleham 169 all out; Lindum 156 all out, Woodhall Spa 225 all out; Louth 108 all out, Sleaford 110-2; Skegness 81 all out, Market Deeping 176 all out; Spalding 249-9, Grantham 190 all out.
South Lincs and Border League
Premier Division: Bourne 2nds 224-8, Newborough 203 all out; Grantham 2nds 215 all out, Freiston L&L 184 all out; Moulton Harrox 194-0, Boston 192 all out; Sleaford 2nds 122 all out, Long Sutton 123-5.
Division One: Baston 173-5, Orton Park 2nds 95 all out; Billingborough 2nds 49 all out, Ancaster 164 all out; Boston 2nds 131 all out, Moulton Harrox 2nds 153 all out; Heckington 2nds v Grantham 3rds - Grantham conceded; Newborough 2nds 177-9, Spalding 2nds 129-9.
Division Two: Boston 3rds v Uffington - Uffinton conceded; Castor & Ailsworth 2nds 70-6, Belton Park 67 all out; Freiston L&L CC 2nds 131 all out, Skegness 2nds 213-9; Long Sutton 2nds v Spalding 3rds - Spalding conceded.
Lincolnshire County League
Premier Division: Caistor 114 all out, Market Rasen 115-0; Cleethorpes 2nds 156 all out, Outcasts 160-5; Haxey 188-1, Scunthorpe Town 2nds 184-8; Scothern 151-5, Holton-Le-Clay 149 all out.
First Division: Alkborough 78 all out, Messingham 169 all out; Barton Town 134-2, Clee Town Laportes 133 all out; Cherry Willingham 172-8, Louth 2nds 171 all out; Hartsholme 111 all out, Appleby Frodingham 2nds 47 all out.
Second Division: Cleethorpes 3rds 206 all out, Lindum 3rds 208-6; Hibaldstow 143 all out, Normanby Park 243-8; Holton-Le-Clay 2nds 173 all out, Hartsholme 2nds 214-8; Market Rasen 2nds 94-1, Alford & District 93 all out; Nettleham 2nds 236-6, Grimsby Town 2nds 134 all out.
Third Division East: Alford & District 2nds 40 all out, Brocklesby Park 290-8; Horncastle 158 all out, Scothern 2nds 207-8.
Third Division West: Brigg Town 195-9, Haxey 2nds 112 all out; Outcasts 2nds 242-9, Caistor 2nds 133 all out.
Lincoln and District League
Premier Division: Ancaster 118-1, Sleaford 113 all out; Nettleham 219-4, Lindum 216-8; Owmby 226-4, Fulbeck 167 all out.
Division One: Aisthorpe 116 all out, Barkston & Syston 142 all out; Caythorpe 158-9, Woodhall Spa 2nds 161-2; Cherry Willingham 174-9, Billingborough 42 all out; Morton 88-5, Nocton 84 all out.
Division Two: Heighington 194 all out, Hykeham 125 all out; Horncastle 71 all out, Heckington 72-2; North Scarle 283-7, Old Lincolnians 159 all out; Sleaford 2nds 141 all out, Bassingham 145-0.
Division Three: Barrowby 141-7, Rustons 255-4; Carholme 203 all out, Waddington 131-4; Gully Cricketers 100 all out, Owmby Trojans 103-9; Reepham 128 all out, Bracebridge Heath 2nds 129-9.
East Lindsey League
Alford & District 59 all out, Grimoldby & District 239-6; Brocklesby Park 179-7, South Bank 176-7; Louth Taverners 124-4, Clee Town Laportes 121 all out; Tetford 169-9, Grimsby Town Development 116-9.