Winger Nathan Thomas got an hour from the off for the second string as he stepped up his bid for a first-team starting spot.
The former Sunderland trainee was given the nod to start by Sam Collins at Billingham Town, as Pools ran out latewinners over Mansfield Town in the Central League encounter.
And he was right in the action, winning the spot-kick that brought about the opener on the half hour.
A typical darting run down the left drew Tom Sloane into a challenge and Thomas went tumbling
One of four trialists named in the starting XI -Tyler Harvey - stepped up to slot home.
Harvey, who scored twice against Pools in the final game of last season for Plymouth, was hastily registered this week in order to be given a run. And the frontman, currently of non-league Truro, impressed up top.
Centre-back pairing Craig Reid, 30, formerly of Celtic, Motherwell and Dunfermline, and Tolu Kayode, 26, who has been spent the last four years playing in Sweden and Australia, also put in decent shows, alongside a fourth trialist Eddie Rogerson.
Pools lead was to last just quarter of an hour, as Mansfield skipper Lewis Collins curled in a delightful free-kick for 1-1, with on-loan Middlesbrough keeper Joe Fryer given absolutely no chance.
On a cutting pitch and clearly tiring, Thomas was withdrawn by Collins on the hour mark, Devante Rodney replacing him.
It took Pools until the last minute of regulation time to retake the lead - Josh Hawkes, on as a substitute for Kieran Green, curled in from the edge of the area to ensure the reserves secured all three points.