Slazenger seconds battled to the final whistle without reward as experienced Halifax seconds secured a contentious 2-0 victor.
Wingers Matt Birkett and man of the match Richard Whawell were constant threats but the sides were deadlocked at 0-0 at half-time.
Ten minutes from time Halifax gained a penalty flick decision, hotly disputed by Slazenger who had goalkeeper Jonny Walker sent off. Not supprisingly a second goal followed before the end.
