Jack Berry produced career-best figures of 8-95 as Bourne increased their lead in the Lincolnshire Premier League to 30 points with victory over Louth.
Skipper Pete Morgan and Carl Wilson were also in their usual impressive form as Bourne recorded a five-wicket victory.
Berry starred as Louth were dismissed for 210 and Bourne went on to reach their target with nearly six overs to spare.
Morgan’s run-a-ball 91 and Wilson’s 65 not out from 61 balls helped Bourne move closer to the title they last won in 2010.
With just three matches remaining, starting with a top-of-the-table clash at second-placed Bracebridge Heath on Saturday, the title is Bourne’s to lose.
They then host local rivals Market Deeping before travelling to Lindum, but with just one defeat in the league this season it is hard to see the title slipping out of their grasp.
Spalding bounced back from last week’s shocking batting display by posting the highest total of the weekend.
Josh Newton hit 67 and Henry Charlton did even better with a knock of 277-8 against Grimsby.
Newton’s total included 10 boundaries while Charlton hit six fours and three sixes, with Nuwan Jayesena (40) and Charlie Kearns (28) giving good support.
The visitors made a positive start in reply, with Joe Farmery hitting 70, but it was a day when Spalding’s star batsmen proved more effective with the ball than the bat.
Fine bowling from their two opening batsmen saw Grimsby dismissed for 191.
Thivanka Rajaratne (5-27) and Warren Nel (4-50) took the bulk of the wickets, although they have not been at their best with the bat in recent weeks.
Market Deeping, who looked so impressive at the start of the season, saw their poor spell continue with an 80-run defeat at Lindum.
Mehul Adatia took 5-38 as Lindum were bowled out for 199 but Deeping again went cheaply with Chris Jones top-scoring with a modest 26.
Struggling Billingborough were far better with the ball than the bat as they were heavily beaten by high-flying Bracebridge Heath.
Wicket-keeper Andy Scott took five catches as second-placed Bracebridge Heath were restricted to 157 and Billingborough’s batting line-up then suffered a shocking collapse once he was dismissed for 18.
At that point Billingborough were 25-3 but they were dismissed in a little over 15 overs with Scott scoring more than half of their paltry total of 32.