The Lincolnshire Premier League title race took another twist as leaders Bracebridge Heath and second placed Boston both suffered defeats.
Bracebridge lost by 22 runs to Woodhall Spa, despite Ashley Schultz taking 5-49 to restrict Woodhall to 182-8.
Lindum thrashed Boston by 176 runs, Luke Robinson making 117 not out in the hosts' 239-5 before Stuart Turner's 7-38 helped dismiss Boston for only 63.
That defeat allowed Bourne to climb to second with a 162-run win at Skegness.
Pete Morgan's unbeaten 110 and 60 from Conrad Louth saw Bourne make 234-6, with Charlie Hopkins then taking 6-28 as Skegness were all out for 72.
The mid-table battle has also intensified with only six points separating Grimsby in fourth from eighth-placed Sleaford.
Sleaford are one point behind Hartsholme following a 29-run defeat by them, Henry Rush taking 5-28 as Sleaford were bowled out for 117 in reply to Hartsholme's 146-9.
Louth leapfrogged Market Deeping thanks to a 45-run win at Outgang Road, Dave Clarke top-scoring with 59 in the visitors' 242 and Tom Andrews taking 5-80, before Deeping were all out for 197 despite 70 from David Gillett.
Grimsby's Richard Antcliffe and Harry Warwick and Nettleham's Dan Wright all made half-centuries, only for their match at Mulsanne Park to fall foul of the weather.
Lincolnshire Premier League
Results for Saturday, 6 August:
Cross O'Cliff Court: Woodhall Spa 182-8 (Schultz 5-49); Bracebridge Heath 160
Richmond Drive: Bourne 234-6 (Morgan 110no, Louth 60); Skegness 72 (Hopkins 6-28)
St. Giles Avenue: Lindum 239-5 (Robinson 117no); Boston 63 (Turner 7-38)
Outgang road: Louth 242 (Clark 59, Andrews 5-80); Market Deeping 197 (Gillett 70)
Augusta Street: Grimsby 215 (Antcliffe 66, Warwick 51); Nettleham 158-3 (Wright 53) - match abandoned
Ashby Avenue: Hartsholme 146-9; Sleaford 117 (Rush 5-28)