Two of Portugal's top three teams from last season, Benfica and Braga, opened the new campaign with a 2-2 draw.
Benfica scored the opening goal early in the second half courtesy of Eduardo Salvio before giving it back five minutes later on a Lorenzo Melgarejo own goal.
Braga seized the lead in the 63rd through Mossoro, but had Ferreira Douglas sent off in the final 20 minutes, allowing Oscar Cardozo to convert the equalizing goal from the penalty spot.
Defending champions FC Porto were held to a 0-0 draw at Gil Vicente, while Sporting Lisbon's visit to Guimaraes also failed to produce a goal.
The new season opened on Friday with Olhanense claiming a 2-1 win over Estoril as Fernando Alexandre netted the winning goal in the 59th minute.
Maritimo's Joao Guilherme scored the lone goal in the 87th minute of his team's 1-0 triumph at Rio Ave, Moreirense salvaged a 1-1 draw at Pacos Ferreira, while 10-man Setubal came from two goals down in the last 15 minutes to claim an unlikely 2-2 draw at Nacional.
The weekend's action came to a close on Monday as Academica pulled off a stunning comeback to rally for a 3-3 draw with Beira Mar.
Joao Real was sent off after just seven minutes for Academica, and Beira Mar took advantage by jumping out to a 3-0 lead in the first 60 minutes.
But 10-man Academica stormed back with a goal from Salim Cisse before Edinho netted two goals in the last 10 minutes to claim a surprising point for his side.