Spalding opened up a 14-point lead in the Premier Division following an eight-wicket win over Boston 2nd who slipped to third behind Sleaford 2nd.
Ben Troops made 52 during Boston’s 158-7 but Josh Newton’s unbeaten 83 saw Spalding to victory.
Sleaford notched up the division’s highest total with 232-5 – Luke Hollingworth with 68 and Simon Godby unbeaten on 75 – before bowling Market Deeping 2nd out for 100.
James Ferrow (74no) and Simon Prentice shared an unbeaten stand of 110 to take Stamford Town to 206-6.
Ben Peck then took 5-22 as Long Sutton were bowled out for 137.
Danny Ashley also took five wickets for Grantham 2nd in their victory over Billingborough while in the closest game of the day, Bourne 2nd beat Belton Park by just 18 runs.
In Division One, Freiston made the highest total of the day and Zeeshan Saeed the only century in their win over Grantham 3rd.
This moves Freiston into second behind Spalding 2nd who were involved in a nail-biting finish that saw Skegness 2nd lose by just 11 runs.
Baston are third following a 10-wicket win over Billingborough.
Welby Cavaliers move into fourth after Simon Meadows’ 86 helped them to 207-5.
Will Charlesworth hit back with 70 for Heckington but Vidit Matta claimed five wickets to help bowl the visitors out for 139.
Claypole continue to forge ahead in Division Two, building a 24-point lead over Graves Park who do have a game in hand.
James King made 56 in Claypole’s 206-8 then Adam Clarke took 5-9 as Belton Park 2nd were all out for 130.
Graves Park, meanwhile, were involved in a League Trophy game in which they overcame Boston 3rd and Moulton Harrox beat Timberland in the same competition.
Billingborough 112 (Ashley 5-35), Grantham 2nd 113-3.
Boston 2nd 158-7 (B Troops 52), Spalding 159-2 (Newton 83no).
Stamford Town 206-6 (Ferrow 74no), Long Sutton 137 (Peck 5-22).
Sleaford 2nd 232-5 (Hollingworth 68, Godby 75no), Market Deeping 2nd 100.
Bourne 2nd 220-8, Belton Park 202.
Billingborough 2nd 57 (Conlon 5-23), Baston 62-0.
Freiston 286-7 (Saeed 100), Grantham 3rd 175-7.
Welby Cavaliers 207-5 (Meadows 86), Heckington 139 (Charlesworth 70, Matta 5-30).
Spalding 2nd 162, Skegness 2nd 151.
Claypole 206-8 (King 56), Belton Park 2nd 130 (Clarke 5-9).
Pinchbeck beat Long Sutton 2nd by 10 wickets.
Timberland 109, Moulton Harrox 113-0 (M Barnett 58no).
Boston 3rd 67 (J Morris 5-16), Graves Park CC 68-1 (Ashton 50no).