They travelled to Carlisle to face Cumberland CCC in their final match of the campaign, knowing that a victory would almost certainly guarantee them top spot, ending the contest with a 53-run success.
Dominic Brown came into the side in place of Adam Tillcock and Alex Moor replaced James Kimber.
The start on day one was delayed until after lunch due to wet conditions, and upon winning the toss Lincolnshire elected to bat.
Scoring runs at any great pace proved difficult, and openers Joe Kendall and Jack Timby were dismissed with only 26 runs on the board.
Louis Kimber settled in and played steadily and was the only batsman to play with authority.
Bilal Shafayat and Dominic Brown were dismissed with the score on 92 for 4.
Kimber and Dan Freeman then took the score to 143 before Kimber fell for a fine 68.
Bad light ended play in the late afternoon with Lincolnshire on 182 for 5 off 78 overs, Freeman 33 not out and Carl Wilson 19 not out.
Persistent rain on day two ruled out any prospect of play and Lincolnshire’s chances of victory receded rapidly.
On day three play commenced after a delayed start at 11.15am.
Lincolnshire continued their first innings, finally declaring on 231 for 8 after 87 overs, thereby securing two vital batting points.
Cumberland forfeited their first innings and Lincolnshire their second innings, thereby leaving Cumberland requiring 232 runs to win in a minimum of 78 overs and Lincolnshire requiring 10 wickets for victory.
Early wickets by Curtis Free, Alex Willerton and Dominic Brown reduced Cumberland to 59 for 3.
A stand of 47 took the home side over the 100 mark but a spell where five wickets fell for 20 runs put Lincolnshire firmly in control, and at 126 for 8 were within sight of victory.
The final two Cumberland wickets fell for the addition of a further 52 runs as they were dismissed for 178 inside the final hour of play, Lincolnshire winning by 53 runs, Willerton and Free taking four wickets apiece for 56 and 34 runs respectively.
Lincolnshire took 18 points from the match and for the third successive season won the Eastern Division title.
They now face Western Division winners, Berkshire, in the four day play-off final at Banbury commencing on Sunday, September 16 (10.30am).