They made one change from the side that had comprehensively beaten Northumberland, with Harry Warwick (Cleethorpes) replacing the unavailable Ross Dixon on his home ground.
Hertfordshire won the toss and elected to bat in front of a substantial crowd.
Lincolnshire’s bowlers struck quickly as Hertfordshire were reduced to 61 for 4 and then 108 for 7 as Alex Willerton and Andy Carter. with pace and accuracy. demolished their batting line-up.
No stand was more than 25 runs and inside 46 overs the visitors were dismissed for 143.
Willerton with 5 for 27 in 16.1 overs was Lincolnshire’s most successful bowler with Carter 2 for 24 providing strong back-up.
Lincolnshire had obtained the maximum four bowling points.
When Lincolnshire batted, Louis Kimber and Dan Freeman were dismissed cheaply and at 58 for 2 Lincolnshire needed a strong partnership to put them in a commanding position.
Matt Lineker and Conrad Louth provided this and put on 96 before Louth was dismissed for 34.
Lineker finally fell for a fine 98 (11 fours and 3 sixes) as Lincolnshire lost four late wickets to conclude the day on 210 for 6, with one batting point secured.
Lincolnshire now needed two further batting points to secure the title and immediately Dominic Brown and Carl Wilson set about the Hertfordshire attack.
Runs flowed quickly with forty coming in the first half-hour, and they finally reached 275 for 6 to secure the further two points.
Brown was eventually dismissed for 60, having put on 96 with Wilson.
Lincolnshire concluded their innings after their allotted 90 overs on 345 for 8, Carl Wilson being not out for an excellent 87 off 103 balls.
Lincolnshire had a first innings lead of 202.
Despite losing an early wicket, Hertfordshire made better progress in their second innings as the pitch had now become a fine batting surface and the bowlers had to toil hard for wickets.
Tanveer Sikandar and James Scott putting on 86 for the second wicket before the introduction of Freeman into the attack accounted for Sikandar for 47.
Andy Carter then struck twice to remove Chatfield and Southgate, both caught behind by wicketkeeper Wilson.
Opener Scott was finally bowled by Willerton for 70 and Freeman accounted for Cowell and Palmer.
The second day ended with Hertfordshire on 203 for 7, one run in front of Lincolnshire.
Lincolnshire started day three needing a further two wickets but the Hertfordshire batsmen were not to be dismissed easily.
Kazmi and Kulkarni battled hard and kept the scoreboard moving, adding 68 for the eighth wicket before Willerton removed Kulkarni for 32.
Ben Waring then joined Kazmi in a ninth wicket stand of 64 before Dominic Brown bowled Kazmi for an excellent 79 to add to his first innings score of 41.
The final wicket also fell to Brown courtesy of a fine diving catch by Harry Warwick.
Hertfordshire totalled 342 leaving Lincolnshire needed 141 for victory.
Willerton and Freeman each took three wickets, but Carter and Brown, with two apiece had taken crucial wickets at vital stages of the innings.
Freeman and Kimber opened for Lincolnshire and first Freeman and then Lineker were dismissed cheaply as the total reached 43 for 2.
Conrad Louth then joined Kimber in a stand of 42 before Louth was caught for 31.
Adam Tillcock joined Kimber and they saw Lincolnshire to victory by mid afternoon, Kimber making a fine 54 not out.
Lincolnshire took a maximum 24 points from the match with Hertfordshire taking three.
This victory put Lincolnshire firmly at the top of the Eastern Division table and results elsewhere showed them 25 points clear of second placed Suffolk.
Lincolnshire will now meet Berkshire, the Western Division winners, at Banbury on August 27-30 in the Championship play-off final.
Before that, they will also meet Berkshire on 23 August at Wormsley in the final of the Knockout Trophy.