You could forgive the Rovers chief for being slightly jittery when the fourth official held up a board declaring 13 minutes of stoppage time.
It was due to female assistant Helen Byrne going off ill and a replacement having to be plucked from the crowd.
Despite that distraction, dogged defending from Rovers ensured John Marquis’s second-half header proved the difference - handing Donny just their fourth win in what has been a miserable 2016.
Ferguson admitted that nerves got to him during that large chunk of extra-time.
“I was a little bit nervous at the end,” quipped the relieved Scot.
“What we said at half time was that we just needed a bit more quality and the quality of the goal was outstanding.
“It was a great cross and a great finish, and a goal worthy of winning any game.
“At half-time I just told them to keep plugging away, add a bit more quality and keep the concentration.
“We should’ve won by more than one but I’ll take that.”
Marquis atoned for an early penalty miss by heading home a precise Matty Blair cross but Ferguson understands the need to rectify their troubles from spot-kicks.
Marquis’s miss followed another spot-kick blemish from Andy Williams on the opening day at Accrington Stanley.
He added: “We need to start scoring penalties - that is a problem.”
“But it didn’t knock us and I don’t think it affected us at all.”