Slazenger overcame a sluggish start and an early goal set-back to defeat Harrogate’s second string comprehensively.
Foundations for the victory were laid by the strong mid field work of Dave Kaye and Keith Whittle.
Whittle scored first from a short corner to equalise, Slazenger seemed in control but Harrogate hit back before half-time to trail just 3-2.
Slazenger finally gained full control midway through the second half and powered home.
Kev Windler finished with a hat trick in his debut game for Slazenger and centre-forward Mark Butel bagged a brace while captain Mark Swallow surged forward from the back to wrap up the scoring and beat his goals tally from last season.