Parley moved 11 points clear at the top-flight summit as |they recorded a thumping win, while their counterparts slipped off the pace.
Long-time leaders Wimborne are now playing catch-up with two matches remaining after gaining 12 points from Saturday’s clash with Poole.
Ciaran Quinn (2-26) put the Minstermen on the back foot before Ben Bridgen (62) rebuilt the Wimborne innings by sharing partnerships of 54 with Francis Kerins (15) and 52 with Mike Kitson (44 and 2-30).
Wimborne progressed to 190 for six in the 44th over before Jon Salt (3-13) peppered the lower order to dismiss them for 197 (Mittesh Parab 2-33).
Poole put themselves in a winning position as Salt (42), Lewis Marais (26) and Dave Miller (24) led them to the brink of victory – requiring six from the final over.
But with Salt and Miller falling to the second and third balls of the finale, the match ended in a thrilling tie.