Harris was stopped just short as York restarted well, but Featherstone responded, with Clay Webb denied by Toa Mata’afa’s try-saving tackle before Reynolds’ second penalty levelled the scores on the hour.
Knights’ back-row Oli Field was brought down a few metres short of the line and Featherstone wasted a late drop-goal opportunity as nerves and fatigue built.
Both sides missed drop-goal attempts in extra time through Harris and Ryan Hampshire, before the former found the target to clinch a tense final.
Featherstone: Aekins, Olpherts, Hardcastle, Gale, Wynne, Reynolds, Hampshire, Springer, Jubb, Beckett, Day, Webb, Addy.
Interchanges: Jones, Williams, Vuniyayawa, Arnold.
York: Mata’afa, Brown, Buchanan, Field, Galeano, Hingano, Harris, Martin, McShane, Ta’ai, Dee, Bailey, Thompson.
Interchanges: Cook, Santi, Gannon, Hudson.
Referee: Liam Rush.