The basement-boys were thankful to on-loan Celtic midfielder Callum McGregor who scored twice and also made two goal-line clearances as Notts County battled to a 3-1 win against Gillingham.
McGregor scored either side of the break, while Jack Grealish also got on the scoresheet, while Bradley Dack scored for Peter Taylor's Gills.
"It may have been my 36th birthday yesterday, but I look about 45 now," said Derry. "I've been waiting for that win since I've come through the door and I'm delighted it came under the circumstances that it did.
"I thought the whole team really delivered at a crucial time of the season. I thought at times we showed nervousness, but we scored at critical times.
"There were some magical performances; I don't think you'll see a better third goal at any level.
"Callum McGregor was the difference, he saved us. He scored two great goals and saved us at the other end as well. The goalkeeper was brilliant too.
"People were expecting us to win, because we were under pressure and I'm delighted that we have won. It's not going to be plain-sailing, I can guarantee that. We'll go to Colchester and put another performance in like that."