"I am very disappointed. Sometimes when you cannot win a draw is a good result," said Benitez.
"We were in the last minute, we had a throw-in, then we give the ball away. They counter and we lose a goal.
"If we play to the level we can, we can make fourth but it will be difficult if we do not improve our mental attitude."
The result means Everton can go four points clear if they beat Crystal Palace on Sunday.
Click here to watch the post-match interview