Simon Rees hit a dramatic final-ball four to clinch victory for Suffolk in their MCCA qualifier with Shropshire.
Set 220 to win at Shifnal, Rees faced the last ball, with Suffolk on 216-8, but he swept a boundary to put his side on course for the knockout rounds.
Shropshire, who won the trophy in 2010, reached 219-8, Ed Foster scoring 51.
Suffolk lost opener Tom Huggins for a first-ball duck, but a middle-order 52 from Simon Guy steadied the ship as the game moved towards its exciting finale.
Both of the group's opening rounds had been washed out by bad weather, so the two sides knew a victory at Shifnal was needed to put them ahead in the round robin four-game qualifiers.
Shropshire started shakily, losing opener Richard Oliver for three and pro Bilal Shafayat for a golden duck - in his final appearance for Shropshire after registering with Hampshire.
But Oliver's opening partner Ed Foster kept his nerve, and there were solid contributions down the order - including an unbeaten 40 from Alex Blofield.