The Scottish champions had looked on course to claim the victory after Steven Whittaker handed the home side the advantage, before substitute Matias Fernandez came off the bench to grab a late leveller for the visitors.

The last time the two sides met, the first leg ended in a goalless stalemate in Glasgow before Rangers claimed an impressive 2-0 win away from home, with Whittaker netting a superb solo goal on that occasion.

Smith's men went on to progress all the way to the UEFA Cup final after that meeting almost three years ago and the Rangers boss has every faith in his men to produce the goods once again in Lisbon.

He said: "If you are going on tonight's performance, there was not much between the teams.

"Overall, we created enough opportunities to make us think that we could get a goal over there. It depends on who plays best on the night.

"If we play the way we did for 35 minutes of the second half then I will be happy."

Sporting's results domestically have been lacking but they have impressed on the European stage and will be the happier of the two teams tonight.

Smith was frustrated that his side failed to see out the game, with Sporting finding the back of the net with just a minute to go.

He added: "We were a little disappointed with the first half of the game, our possession was not quite as good as it should have been.

"In the second half we played well until we scored and then we allowed Sporting too much of the ball.

"It culminated in us losing a goal which is very disappointing. We just feel disappointed after dictating most of the second half that we missed out at the end which was a blow for us."

There was a setback for Rangers before a ball was even kicked when Jamie Ness, who was set to be named on the bench, was forced to withdraw from the squad after suffering an injury during the warm-up.

The youngster could now miss out on the crucial Clydesdale Bank Premier League clash against Celtic.

Smith confirmed: "He damaged his groin and is now doubtful for Sunday's game."

Sporting coach Paulo Sergio was satisfied with the result but admits his side will have to at least match tonight's efforts to progress to the last 16.

He said: "First of all we tried to win but at the end of this game a draw is a good result for us.

"We had control of the game and had three or four chances in the first half and Rangers had one.

"They scored a goal from a corner in the second half and we had to take more risks.

"We created chances and got the goal that put us in a better position for the second leg.

"We are still going to have a lot of work to do in that game. We have a lot of respect for Rangers and we will need to do the same, if not more, in the second leg."