Pavlidis scored the only goal of the game three minutes into the second half in the principality, with Monaco handicapped in their comeback attempts as midfielder Moatasem al-Musrati was sent off shortly after.

Benfica, twice winners of the European Cup in the 1960s, will now hope to finish the job in the return leg in Lisbon next Tuesday, February 18.

The winners of this tie will face a huge challenge in the last 16 against either Liverpool or Barcelona.

Benfica, who are currently second in the Portuguese league behind Lisbon rivals Sporting, were hoping for a repeat of their victory in Monaco in the league phase in late November.

They came from behind twice to win 3-2 on that occasion, aided by the sending-off of Monaco defender Wilfried Singo early in the second half.

This time they went ahead on 48 minutes, bringing the game to life after a first half of few chances at the Stade Louis II.

Pavlidis got goal-side of Mohammed Salisu to latch onto a pass in behind the home defence, before coolly lifting the ball over goalkeeper Radoslaw Majecki to score.

The Greek international centre-forward has now found the net six times in his team's last five Champions League outings, a run which includes a hat-trick in the dramatic 5-4 loss to Barcelona last month.

That was the only goal of the game, but Monaco had Libyan midfielder Al-Musrati harshly sent off in the 52nd minute.

The new loan signing from Besiktas in Turkey gestured to the referee calling for a yellow card after his teammate Breel Embolo had been fouled.

However, Al-Musrati was himself cautioned, and having already been booked he was sent for an early shower.

Having started their Champions League campaign with a win over Barcelona in September, Monaco have now suffered four defeats in their last five European outings.

They will need to get back to winning ways next week, otherwise their hopes of reaching the last 16 will be dashed.