Rovers raised their game in the second half and pulled two goals back via Josh Bharier and Dovi Vogel.
But any hopes of a Rovers recovery were ended when Hershkorn made the game safe, reacting quickly to a parried Jake Saunders shot.
Camden manager Nick Kagan told JC Sport: "It was a good day for us, despite a little scare, and hopefully we now one foot in the quarter-finals."
"Credit to Rovers, and especially their keeper who was probably man of the match for making a string of good saves."
Rovers boss Jeremy Brown told JC Sport: "I think, considering how many players we had out today, we did a good job. In the first half we were very poor and conceded from two set-pieces and went into half time 3-0 down.
"We were much better in the second half and unlucky not to come away with a point."
GROUP A STANDINGS:
Camden Park Pl. 4. Pts. 4
L’Equipe Pl. 1, Pts. 1
Norstar London Raiders C Pl. 0, Pts. 0
London Rovers Pl. 1, Pts. 2