St Albans City showed a strength in depth as substitutes Rhys Murrell-Williamson and Charlie Walker pounced inside the last 20 minutes to secure a 3-1 win over Weston-super-Mare at Clarence Park.
It made it three wins from three in the Vanarama National League South season and sent Saints soaring to the top of the table.
The home side started positively with Sam Merson heading a Ben Herd cross well wide.
The striker then almost opened the scoring in the 10th minute when he saw his effort heavily deflected, but Purnell in the Weston goal got down well low to his right to deny the hosts.
However, St Albans and Merson would not be denied and Zane Banton’s pass was struck powerfully across Purnell into the corner of the net.
Weston, who had so far struggled to get a foot hold in the game, found themselves level seven minutes later.
A Weston attack down the left saw the ball fall to Danny Greenslade three yards outside the box, the defender took a touch before seeing his attempted cross blocked by Solomon Sambou’s left arm which was low and close the midfielder’s body.
Referee Will Finnie awarded the visitors a spot-kick for handball, although it looked to be a harsh decision on the home side.
Weston Stalwart Dayle Grubb stepped up and confidently put the spot-kick low to the goalkeeper’s right to level the scores.
Both sides struggled to make inroads in the final third, although Shaun Lucien did unintentionally go close for the hosts with 10 minutes left in the half when he struck the bar with a cross.
Merson was forced off at the interval after picking up a hamstring injury, with former Aldershot striker Walker replacing the in-form man.
Weston had plenty of possession but couldn’t find a way through a resolute St Albans defence.
It was a game of few clear openings for either side, although St Albans’ David Noble saw his free-kick from 30 yards spectacularly tipped wide by Purnell just past the hour mark.
The game eventually changed on an inspired substitution from the home side.
Murrell-Williamson replaced Banton and immediately played a short one-two from the corner with Noble before hitting a superb effort that curled past Purnell and into the far corner.
The substitute had been on the pitch for less than 10 seconds when he found the net.
Weston looked to push forward in search of an equaliser, and were denied in the 86th minute when Baldwin’s towering header was cleared off of the line by Percy Kiangebeni.
However, St Albans put the victory beyond doubt two minutes later.
A quick break forward eventually saw Murrell-Williamson play the ball into the path of Lucien in the Weston box, and the wide-man hit an effort that looked to be heading wide until Walker stuck out a boot and diverted the effort past Purnell and into the net.