Kieran Murtagh's stunning first senior goal had given Yeovil an early lead and Gavin Tomlin saw a penalty saved by Alex Smithies as the visitors dominated early on.
But Theo Robinson levelled for the Terriers after 33 minutes, before Collins nodded home Lionel Ainsworth's cross in the 64th minute to complete the fightback.
Yeovil started superbly and went in front after six minutes when Murtagh blasted the ball home from 30 yards after a Danny Schofield corner had been cleared straight to him.
Tomlin was then denied from the spot after Lee Peltier had tripped Nathan Smith in the penalty area and Robinson made Yeovil pay by converting Anthony Pilkington's cross.
The Glovers continued to have the better of proceedings after the break but were undone when Collins stole into the box unmarked and planted a powerful header beyond Alex McCarthy.