Potton’s place in the final – being held at their own ground, The Hollow – came after Waresley conceded their semi-final.
Flitwick progressed to the final when they defeated Langford by three runs in a high scoring match last Friday evening.
Batting first, Flitwick scored 165-5 from their 15 x 8 ball overs.
Thomas Westwood bowled county opener George Thurstance for a duck but that brought George Nadeera Nawan early to the crease. He went on to score an unbeaten 102, reaching his century with a boundary off the last ball of the innings.
A spirited reply by Langford saw them fall just three runs short scoring 162-4.
Adam Parkins made 79, but his innings was hampered when he had to have a runner due to a leg strain. Harry Jerome added 39 and Earl Lee made 30.
The final on Friday, July 8 starts at 6pm and all proceeds from the collection will go to local organisations and charities.
Waresley progressed to the semi-finals of the East Beds Senior Shield with a 28 run win at Ickwell.
Waresley chose to bat first and despite good knocks at the top of the order from Alex Scully (31), Alex Watkiss (21) and Sam Johnson (23) an impressive 4-24 spell from Kandasamy Krishnaruban saw them restricted to 148-6.
Ickwell’s reply started reasonably well and Steven Proudman made a half century at number three. However no-one below him could add runs and they closed on 120-9.
Waresley face Potton or Blunham in the semis. The other semi-final sees Biggleswade take on Bedfordshire U17s.
In the U18 Knock-Out Competition on Monday Blunham 87-10 lost to Ampthill 88-4.