They were denied when Dorset chased down a second innings 81 to win the three-day match by nine wickets just in the nick of time - the ground being submerged by a downpour soon after stumps were drawn.
Only 30-overs play was possible on day 1 with Dorset, put into bat, closing on 136/1, emerging Parley batsman Kieran Laird (66) and Harry Fairchild (46). Bournemouth left-hander Ben Rogers (68), Parley's Sam Rook (28) and Freddie Pittaway (Ferndown Wayfarers)(37) weighed in as Dorset went on to total 339 (Tom Southcott 3-55).
Bournemouth left-armer Conor Smith (4-42) and fellow spinner Tom Munnings (4-46) sent down a massive 43 overs as the IWCB was dismissed for 174 - Ventnor's Sam Mills (44) top scoring, supported by Ollie Cheeseman (34) and mainlanders Josh Carpenter (27) and Neil Shelar (24)
Smith enforced the follow on and finished with match figures of -139 off 48 overs as the Islanders fought hard to reach 248, Basingstoke's Shanton Shahane (79) leading the way.
It left Dorset needing 84 to win, but the an eye on the incoming weather, openers Archie Frost (30) and Laird (41 not out) scored 53 in nine overs to set up a win just before the rain came.
Dorset and the IWCB meet again in a T20 double header at Hamworthy on Sunday, before Dorset entertain Cornwall in a three-day county championship match at Wimborne on Tuesday August 1.