Porto continued their march to the Liga Sagres title with a 2-0 win over Braga on Sunday, while Benfica beat Vitoria Guimaraes.
Braga finished second last season to qualify for the Champions League and were one of the few teams who may have been expected to trouble Porto.
But the runaway leaders made it eight wins from their last eight matches to stay 11 points clear at the top of the table.
The hosts kept Porto out in the opening 45 minutes at the Estadio municipal de Baga, but a second-half brace from Argentine Nicolas Otamendi helped Porto to a straightforward victory.
The defeat leaves Braga sixth and in danger of going from the Champions League group stages to missing out on European football altogether next season.
Benfica continued their seemingly doomed title defence with a 3-0 win at home to fourth-placed Vitoria Guimaraes.
Brazilian Sidnei struck first in the 24th minute at the Estadio da Luz, before former Valencia man Pablo Aimar and Carlos Martins completed the scoring.
Naval beat Academica 3-1 at Estadio Municipal Jose Bento Pessoa to climb off the foot of the table with just their third win of the season.
Visitors Academica got off to a disastrous start when Pape Habib Sow was sent off after giving away a penalty in the 21st minute.
Kevin Gomis converted from the spot to give Naval the lead.
Michel Simplicio struck to double the hosts’ advantage five minutes before the break.
A second-half comeback appeared to be on the cards when Gomis fouled inside the box and followed Sow in making an early exit.
Moudou Sougou dispatched the penalty to make it 2-1 six minutes into the second half.
But Academica were unable to find another breakthrough and Giuliano struck to ease the nerves for Naval with three minutes remaining.
Portimonense slid to last place after losing 2-0 away to Rio Ave, with Joeo Tomas and Yazalde Pinto finding the net for the hosts.
A last-minute goal from Venezuelan Mario Rondon helped Pacos de Ferreira beat Maritimo 1-0.