Tom Shorthouse took his total runs for the season past 700 with the Lincolnshire ECB Premier League’s only century of the weekend.
Supported by 77 from Tim McIntosh, Shorthouse helped Sleaford to a victory over Skegness that kept their side in third place and still in touch with the top two, who play on August Bank Holiday.
Chris Graser hit 56 for the seasiders who finished 218 for seven, a total Sleaford overtook for the loss of only two wickets.
Market Rasen’s losing draw at home to Louth put them above Skegness and 14 points up on the bottom two.
Matt Hamilton made 86 and Graham West an unbeaten 51 as Louth recorded the day’s top total of 293 for six.
Rasen reached 50 without loss and steady batting down the order saw them finish on 227 for eight, Nic Keast taking his first Premier League five wicket haul for Louth.
Grantham scored another good victory, this time over Bourne, to take their season’s points over 200 and open up a 42 point gap over the bottom four in the table.
Dan Freeman hit 91 and Rohan Nurse an unbeaten 85, their partnership putting on 101 for the third wicket to leave Bourne chasing 278 for four.
Joe Peck and Freeman then took three wickets each as the visitors’ final wicket fell on 165.
Grimsby slipped further into trouble after a five wicket defeat by Lindum at Augusta Street.
The home side were bowled out for 146 before Luke Robinson added another 66 to his rapidly growing runs total to help his side to victory and leave Grimsby 13 points behind 10th placed Skegness.
With four matches to go, Spalding are now well adrift at the bottom after going down by seven wickets to Market Deeping.
Results: Spalding 113, Market Deeping 117-3; Grimsby 146, Lindum 149-5 (Robinson 66); Grantham 278-4 (Freeman 91, Nurse 85no), Bourne 165; Louth 293-6 (Hamilton 86, G West 51no,), Market Rasen 227-8 (Keast 5-67); Skegness 218-7 (Graser 56) Sleaford 222-2 (Shorthouse 110, McIntosh 77).