Tevez struck in the 87th minute in France as United claimed a 1-1 draw from the first leg of their Champions League last-16 tie.
"I felt we controlled the game for most of it. They had a few chances and stuck the ball in.
"Lyon are a good team and we know we have to concentrate 100 per cent."
Ferguson told Sky Sports: "I think we showed our determination to try to get back.
"We lost a goal out of nothing. We were in complete control and it knocked us back a bit.
"They defended very well and made it difficult for us but I think we deserved it without question.
"There was an urgency to get back in the game and I think we are best in that situation."