The Saints came from behind to secure the three points, overturning Carlton Morris' early strike to make it 17 games without defeat. Despite being forced into an early change, Derby showed intent but were ultimately unable to capitalize on their chances.
A sweeping Saints attack led to Scienza's equalizer, before Harwood-Bellis headed home the winner from a Ryan Manning free-kick. The win cements Southampton's position in the play-off spots, while Derby's defeat leaves them three points adrift.