Pools beat Dover Athletic 3-2 after trailing 2-0 at half-time.
Hignett got his subs spot on and Molyneux was introduced to to devastating effect.
“It’s easy to sum up,” the manager told the club’s website. “It was a bad first half and a good second half.
“We weren’t quite at it in the first half, but credit to the lads - we got them in at half-time and changed to a different system and we looked like a different team.
“I told the lads at half-time that if we got one goal that Dover could go, and they did because this is a tough place to come.
“When we got that goal we had the momentum and I fancied us to go on and win it.
“For Josh (Hawkes) to put the two penalties away the way he did is a great testament – he’s got a cool head on young shoulders.
“Then it was a brilliant finish from Luke Molyneux. I thought he made a real difference when he came on and he just passed it in to the corner, no panic about him.”