Goals from Tyler Harvey and Conor Hourihane meant that Plymouth are just two points behind York, who are in sixth place, and Sheridan was pleased with the performance from his team.
"I thought we scored two excellent goals," he said.
"Tyler Harvey has done what he's been told to do, he broke well from midfield and produced a great finish from a fantastic Nathan Thomas ball.
"I was disappointed on their goal, it's just come back out and we didn't deal with it when we should have been able to see it out.
"The difference between our goals was that we opened them up and played football where as they just read one of our errors and Chris Zebroski has finished off well.
"We've got chance at reaching the play-offs but we've just got to fight. I've told the players that we aren't going to get relegated so go out and relax.
"You could see the effort we put in in tricky conditions on a bobbly pitch but once we got the goals we produced a good team performance."