Manager Daúto Faquirá was without centre-back Mauricio, back in Brazil to visit his sick father, and the influential Vinicius, out through injury.
Mexer came into the back four to partner Jardel while Carlos Fernandes, Cadu and Fernando Alexandre filled the midfield positions.
A goal either side of the interval by Oscar Cardozo and Javier Saviola secured the win for the Eagles. It was a case of mission accomplished for Benfica in an entertaining game to kick off Round 13 of the Liga ZON Sagres.
However, it was far from straightforward for the league champions, especially in the first half as Olhanense gave a good account of themselves at the Estádio da Luz.
Driven forward by the excellent Paulo Sérgio, the visitors caused the home defence plenty of problems in the opening half, with Roberto having to save well from Jorge Gonçalves to prevent the Algarve outfit from taking the lead.
At the other end of the pitch, Olhanense goalkeeper Moretto was returning to his former club, where he had an unhappy spell blighted by several clangers. It must be something to do with the venue, because the Brazilian stopper gifted Benfica the lead with a crass mistake in the 42nd minute.
Oscar Cardozo fired a powerful header towards goal from a Maxi Pereira cross, but the ball was aimed straight at Moretto. After appearing to gather the ball, the keeper somehow let it squirm under his body and over the line.
Shortly after the break, Paulo Sérgio had the ball in the net, but his celebrations were cut short as the strike was ruled out for offside. A harsh decision and, from that moment onwards, Benfica rarely looked in danger of surrendering their lead.
A more composed second-half performance was rewarded by a repeat of a goal that was seen many a time last season. Carlos Martins took a corner, David Luiz flicked the ball on at the near post and Argentine striker Saviola ghosted in at the far post to head home.
The victory was Benfica’s eighth triumph in nine home matches. Olhanense, still without an away win this season, dropped to 10th place.
They will be looking to return to winning ways. Their last league win was against V.Setúbal in early October, when they entertain Nacional (Madeira) on December 19.
Central defender Jardel was disappointed with the outcome and regrets the lack of goals by the Algarve side in the first half.
“We had plenty of possession in the first 20 minutes, the best chances were ours but we did not score,” said the Brazilian player.
