A four-wicket victory over Grantham put Woodhall clear by four points over Bracebridge Heath, who went down by just 10 runs at Lindum.
And Steve Crossley’s unbeaten 93 powered Grimsby to a four wicket-win over Market Deeping, who dropped a place to fourth.
Lindum batted first at home to Bracebridge and finished on 211 for seven, opener Charlie Tomlinson hitting 66.
Bracebridge lost a wicket with just two on the board but on 147 for four looked in control until Oliver Smith joined the attack to take the next five wickets for 37 runs, including that of Brett Houston who made 72.
Bowlers Matt Carter and Matt Bradley fought back but the final wicket fell on 201, Smith with five for 50 off 13 overs.
At Grimsby, Market Deeping had 53 on the board before the first wicket fell and were 142 for four when Hayden Tice began a bowling spell that brought him four wickets and reduced the visitors to 179 for eight.
A run out and a fourth wicket for Lee Charlton made it 185 all out, Chris Jones making 50.
Grimsby then found themselves 25 for three but Michael Brown and Crossley took the score to 74 and Crossley and Brendan Volley (36) added 76.
The Grimsby wicketkeeper lost two more partners but saw his side to victory with 93 off 96 balls and 10 overs to spare.
Skegness find themselves in the bottom three, just two points up on Grantham after losing heavily to Bourne.
This win lifted Bourne to third but a 33 point gap has opened up below the top two.
Conrad Louth hit 59 of Bourne’s 221 for nine while Tom Cuthbert made 50 for Skegness but couldn’t prevent the seasiders collapsing to 136 all out.
At Market Rasen, Matt Rutherford took his total of wickets for the season past 50, claiming five Spalding scalps in a tight game that saw the visitors miss their target of 190 by just 13 runs with two wickets remaining.
Spalding picked up valuable points for the draw but are still 24 behind Grantham.
Rohan Nurse made 53 but Malinga Bandara’s six for 27 restricted the Grantham scoring at Jubilee Park, where Woodhall were left chasing 163, a target they overtook for the loss of six wickets, Dan Freeman claiming four victims and Sam Evison hitting 71 for the new league leaders.
At Sleaford, the home side moved back above Louth after putting their opponents in to bat.
Louth found the going tough against some tight bowling, in particular Cameron Hall who bowled eight overs with five maidens and took two for five.
The final wicket fell on 151 and Tim McIntosh got back among the runs with an unbeaten 86 that took him to 709 for the season and Sleaford to a nine wicket win.
Results: Market Rasen 190-8 (Nel 5-54), Spalding 177-8 (Smith 64no, Rutherford 5-43); Bourne 221-9 (Louth 59), Skegness 136 (Cuthbert 50); Grantham 163 (Nurse 53, Bandara 6-27), Woodhall Spa 166-6 (Evison 71); Louth 151, Sleaford 153 -1 (McIntosh 86no); Lindum 211-7 (Tomlinson 66), Bracebridge Heath 201 (Houston 72, Smith 5-50); Market Deeping 185 (Jones 50), Grimsby Town 186-6 (Crossley 93no).