Everton manager David Moyes expects to be without key midfielder Marouane Fellaini for the rest of the season and to add to his frustration their Europa League hopes are hanging in the balance.
Moyes' side seemed to shrug off the loss of Fellaini, who needs ankle surgery, by racing into a two-goal lead against Sporting Lisbon, thanks to Steven Pienaar and Sylvain Distin. However the game took a dramatic twist with four minutes remaining when Miguel Veloso scored from the spot in this round of 32 first leg match.
Moyes said: "The perspective of the game changed. I thought we were more liable to win 3-0 than 2-1. We looked as though we were trying to conserve our energy rather than going for another goal."
The penalty kick was awarded at Goodison Park after Distin had floored Liedson as he tried to surge forward, and the defender was sent off in the process.
It means Everton now face a difficult return match in Portugal a week on Thursday after looking so comfortable for so long.
Moyes added: "Sylvain had a difficult pass to deal with but we should never have put ourselves in that position. We should have been looking to get forward.
"We did enough to be 2-0 in front and I did not see a goal coming. But it was not to be. It keeps the game alive. That's football.
"We are disappointed we have not seen the job through, which we should have done. We gave Sporting an opportunity when it looked as though they might not have one."