Aiden McGeady was Celtic's UEFA Champions League hero as they beat Benfica 1-0 in Glasgow on Tuesday to keep on course for qualification from the group stages.
The Republic of Ireland international sealed a man of the match performance with the only goal of the game on the stroke of half time - although his shot took a wicked deflection off Brazilian defender Luisao.
Celtic moved level with Ukraine side Shakhtar Donetsk, who lost 3-0 to AC Milan, on six points in Group D to maintain their hopes of repeating last season's run to the last 16 of the competition.
But the result almost certainly finished the qualification hopes of Benfica, who finished with ten men after Cameroon international Augustin Binya was sent off near the end, as they sit bottom of the section on three points with only two games left.
Oscar Cardozo had scored the only goal of the game when the sides met less than two weeks ago in Lisbon, and he nearly opened the scoring in the seventh minute.
Collecting the ball 18-yards out with his back to goal, the big Paraguayan striker swivelled before smashing a shot, which required Celtic's Polish goalkeeper Artur Boruc to push away low to his right.
Celtic centre-half John Kennedy should have put his side in front in the 10th minute instead of heading wide from six-yards, after Paul Hartley's free-kick found him unmarked at the back post.
But it was Benfica who were doing most of the pressing in the early stages.
Cardozo was again denied by Boruc in the 12th minute, the Polish international stopper somehow stretching to tip the striker's powerful effort from 16-yards over his crossbar.
At the other end Scott Brown forced Benfica's goalkeeper into action in the 17th minute with a left-foot shot from 25-yards, which Quim did well to turn round his post at full-stretch.
Quim was again called into action in the 20th minute to palm away Scott McDonald's fine shot on the turn from the edge of the penalty area.
Suddenly it was the home side who were looking the more dangerous.
In the 23rd minute McDonald was again denied by Quim, who stuck out a foot to divert the Australian's goalbound shot away.
Throughout the first half McGeady had posed a constant threat to Benfica on the left-wing and in the 45th minute he gave his side a half time lead.
Czech midfielder Jiri Jarosik spread the ball wide and the 21-year-old took a touch, skipped inside and blasted a right-foot drive beyond Quim, with the aid of a deflection off Luisao.
Although the match was very open at the start of the second half there were few chances in front of goal.
Cardozo had an excellent opportunity to level in the 62nd minute when he met Leo's deep cross to the back post but his header flashed just wide, with Boruc rooted to the spot.
Celtic left-back Lee Naylor was then required to head off his own line when Brazilian defender Edcarlos' header beat Boruc in the 68th minute.
As the game suddenly burst into life Celtic nearly doubled their advantage two minutes later.
McDonald played a beautiful pass into the path of Brown and his shot required Quim to palm away.
As time ran out for Benfica they began to throw men forward.
Their chances of a late equaliser diminished, however, when Binya was shown a straight red card in the 86th minute by Swedish referee Martin Hansson for a stamp on Brown.