In the opening game, Paul Cooper's fourth-minute goal for City of Portsmouth rocked Crostyx but it was Cooper's indiscipline and temporary suspension just before the interval which tipped the scales, with the Essex club staging a fight back with late goals from Paul Dover and Nick Duck to win 2-1.
Whitchurch, the only Welsh team in the National League and also fighting for survival, were in impressive form against Bath Buccaneers. Although twice pegged back by the West Country club on the break, Whitchurch prevailed with second-half goals from Daniel Jones, his second of the game, and a cracking final goal from Mark Lewis.
Earlier, after Huw Savage had given Whitchurch the lead, Bobby Seabrook, the former Havant forward, equalised for Bath. Jones then put the Welsh side back into the lead before Peter Wheeler getting the second equaliser.
A sixth-minute goal from Richard Gorely gave a well organised and well supplied Blueharts a deserved win against the host club, Olton and West Warwick.
In the women's tournament in Clifton, Reading, who failed to qualify last year, scored goals from Karen Emmas and Denny Shorney, to beat the local side Redland 2-0 to draw first blood.
MEN'S NATIONAL INTER-LEAGUE PLAY-OFFS (Olton): Pool A: Olton & West Warwick 0 Blueharts 1; Bath Buccaneers 2 Whitchurch 4. Pool B: City of Portsmouth 1 Crostyx 2; Norton 1 High Wycombe 1.
WOMEN'S NATIONAL INTER-LEAGUE PLAY-OFFS (Clifton): Redland 0 Reading 2; Old Loughtonians 1 Aldridge 3.Reuse content