Benfica led Celtic 1-0 in the early stages on Thursday night.
Jhon Duran scored from the penalty spot in the fifth minute.
Dane Murray fouled Duran inside the box, and the referee pointed to the spot.
The match took place at Estadio da Luz in Lisbon, Benfica's home ground.
Benfica started with three points, while Celtic started with zero.
Benfica had won six home games and drawn one before this match.
Celtic lost their first Europa League game 3-1 to Ferencvaros.
Jhon Duran played for Benfica, while Camilo Duran played for Celtic.
Benfica left Vangelis Pavlidis on the bench despite his 14 goals this season.
Cameron Carter-Vickers missed the trip to Lisbon through injury.
A Benfica win would lift them to six points from two games.
Tap to read the full explainer, with lineups, form, and stakes.
Get the full breakdown, key numbers, and what happens next.
Read on Rive News