The home side led until the 80th minute but were sunk by two goals in three minutes - condemning them to a third straight defeat.
"We were well beaten," Ferguson said. "I'm firmly of the opinion that after 16 matches you deserve to be where you are in the league table.
"We are well aware of the position we are in and know the challenge we have ahead. We need to win 13 of our remaining 30 games to keep ourselves in this league.
"I believe I have a good squad and that we can overcome any blows we've suffered so far, but you better ask the players if they can."
Ferguson also paid tribute to winger Wilfred Zaha who created Palace's winner, adding: "He is the best player in this league and will go to the top.
"He was unplayable at times but we didn't help ourselves by endlessly giving away the ball due to poor passing."