Deeping lost to Boston by just nine runs and fellow challengers Grantham’s game was called off at Louth.
But it was Skegness that witnessed the drama of the day as Ray Jordan became only the second bowler in the league’s history - and the first since 2011 - to take nine wickets in a match.
The previous nine wicket haul went to Mark Dixon of Bourne who took nine for 31, but Jordan smashed those figures with nine for 15, including a hat trick, an onslaught that saw opponents Grimsby only just miss out on the league’s most unwanted record as they collapsed to 27 all out, three more runs that Caistor scored in 2002.
Earlier, Skegness had finished on 230 for seven, Dylan Labuschagne making 55 and Norman Brackley 76 and the 20 points gained with the help of West Indian signing Jordan moved the seasiders up two places and out of the relegation zone.
Boston’s victory over leaders Deeping came after the Mayflower team had been bowled out for only 147 at Outgang Road, Mehul Adatia and Lee Peacock each taking three wickets.
Tim Bell and Riley Orr then saw off Deeping’s top six for 62 runs, only for the lower order to dig in, Ashley Fisher hitting a useful 35 but when the ninth wicket fell, Deeping still needed 30 runs.
Peacock and Josh Smith took up the challenge and the score slowly mounted but with nine runs needed, Smith was bowled by Paul Deans leaving Peacock unbeaten on 21.
This victory took Boston into the top half of the table while Deeping now lie second, seven behind Sleaford, with Bracebridge Heath third after a dazzling century from David Whapplington, the only ton of the day.
In his first outing as an opening bat, Whapplington hit 101 off 120 balls against Lindum, putting on 121 for the first wicket with Nick John (43).
Paul Cook chipped in with 70 to help his side to 297 for five, a total out of reach of the visitors, who were all out for 134.
Obus Pienaar added another 78 runs to his ever-growing total - now over the 700 mark - as Sleaford finished on 224 for eight, Ollie Burford making 63.
Woodhall Spa were then bowled out for 162, Nick Goacher taking four wickets.
At Nettleham, the home side were bowled out for 90 but took five Bourne wickets before the visitors claimed victory.
Results: Nettleham 90, Bourne 91-5; Sleaford 224-8 (Pienaar 78, Burford 63), Woodhall Spa 162; Skegness 230-7 (Labuschagne 55, Brackley 76), Grimsby Town 27 (Jordan 9-15 inc hat trick); Bracebridge Heath 297-5 (Whapplington 101, Cook 70), Lindum 134; Boston 147, Market Deeping 138; Louth v Grantham - cancelled, waterlogged pitch.