Champions Benfica get off to bad start
Striker Miguel Fidalgo put Academica ahead by heading in on 25 minutes after beating defender Sidnei to a Diego Valente free-kick.
Benfica leveled in the 62nd minute with a tap in by Argentine forward Franco Jara from a cross by left-back Fabio Coentrao.
The champions pushed forward for a second goal, but Academica bagged the winner in the last minute of injury-time when substitute Laionel completed a fast counter attack with a delightful long distance effort.
Last season's surprise runners-up Braga beat Portimonense 3-1 at home thanks to goals by striker Matheus, winger Paulo Cesar and midfielder Salino on Friday.
A late penalty converted by Brazilian forward Hulk earned Porto a 1-0 win over Naval on Saturday, while Sporting suffered a 1-0 defeat at Pacos Ferreira.