Benfica bring a 14-game unbeaten domestic record into the game, but the hosts have been threatening to break into the European places with their performances this season.
Match preview
Roger Schmidt's side have been excellent domestically, but woeful in Europe, and many thought it could not get any worse for Benfica after four defeats from four in their Champions League group, but it arguably did.
Benfica were cruising to a comfortable victory over a much-changed Inter Milan side at the Estadio da Luz on Wednesday, leading 3-0 at the break thanks to Joao Mario's hat-trick.
Inexplicably though, the hosts threw their lead away, and Nicolas Otamendi's rash challenge in the box gifted Alexis Sanchez the chance to level at 3-3 from the spot and he duly obliged.
Win or draw though, nothing would have changed, as Benfica still need to beat Red Bull Salzburg on matchday six to at least drop into the Europa League.
That poor form has certainly not crossed over to matters at home though, as Benfica have won 13 of their 15 domestic matches this season, leaving them top of the table on goal difference ahead of rivals Sporting Lisbon.
Benfica's last league outing was one of the most dramatic seen in Portugal for years, as goals four and seven minutes into second-half stoppage time from Joao Neves and Casper Tengstedt saw the Eagles complete an astonishing turnaround.
It was an incredible moment for teenager Neves, who was the scourge of Sporting again after scoring in the same minute to equalise in last season's Lisbon derby too, a result which ultimately won Benfica the title.
Newly-promoted Moreirense will look to knock them off their perch at the top though, as well as closing the gap to Braga in the top four.
Moreirense are the best of the rest so far outside of Portugal's four more successful sides, with new manager Rui Borges working wonders after taking over from Paulo Alves, who left after guiding them to promotion.
Despite scoring over half of Braga's tally so far, they are just three points behind, with a pragmatic approach proving the key to their ascent up the table.
Six clean sheets in 11 games - including five in their last six - means Moreirense have been extremely efficient despite only scoring 14 goals.
The hosts have not conceded to an opposing player in the league since Ousmane Diomande scored for Sporting back in mid-September; nine hours of action have passed since.
Sporting, Porto and Braga have been responsible for 80% of the goals Moreirense have conceded this season, suggesting they are capable of remaining as the best of the rest.
Borges's target will be to guide Moreirense into Europe for the first time in the club's history, and a fifth-place finish would ensure that, unless there is a surprise cup winner.
Their previous best finish came in 2018-19, when they finished sixth, but they have not come close to replicating that since, until now.
Moreirense Primeira Liga form:
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Moreirense form (all competitions):
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Benfica Primeira Liga form:
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Benfica form (all competitions):
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Team News
Borges has no reason to change a side that has been performing so well, meaning Joao Camacho may struggle to get back into the side if he is to return from injury.
Camacho was injured in the shock cup defeat to Paredes after coming off the bench, but Moreirense have won all three since in his absence.
A straight red card for substitute Wallisson means he will be out though, as he was dismissed shortly after their late winner at Estrela before the international break, while defender Dinis Pinto is also absent with injury.
Benfica's Antonio Silva was sent off for the second time in the Champions League this season on Wednesday for a wild challenge on Nicolo Barella, but his suspension will be served in Salzburg in two weeks' time.
Full-back remains a problem area for Benfica, with Alexander Bah and Juan Bernat both out, so a back three could be implemented again, with Fredrik Aursnes and Neves playing as unconventional wing-backs.
Recent recruit Orkun Kokcu has been eased back into action after injury, making 12-minute cameos off the bench in both games this week, but he may remain on the bench again here.
Schmidt picked a strong side for their cup tie with Famalicao last week, and he could go with a similar side to that one here.
Moreirense possible starting lineup:
Kewin; Fabiano, Maracas, Marcelo, Pedro Amador; Goncalo Franco, Ofori, Alanzinho; Madson, Andre Luis, Kodisang
Benfica possible starting lineup:
Trubin; Otamendi, Antonio Silva, Morato; Aursnes, Joao Mario, Florentino, Joao Neves; Di Maria, Musa, Rafa Silva
We say: Moreirense 1-2 Benfica
Three of the last four meetings between the sides have seen Moreirense hold Benfica to 1-1 draws, as the visitors have only won four of the last nine head-to-heads, despite the gulf in stature between the sides.