Liga Sagres wrap: Top clubs made to work hard
Porto may have been leading the way in Portugal heading into this encounter, but they were given a thorough examination by Estoril in a 2-1 victory.
Steven Vitoria stunned defending Portuguese champions Porto by giving Estoril the lead in the 10th minute on Sunday before Jackson Martinez inspired his side with a superb second half, setting up Silvestre Varela's equaliser in the 57th minute before scoring himself on the hour.
The winning goal was Martinez's ninth from 11 games this season but his efforts were not enough to stop Porto from dropping down to second on the table on goal difference behind Benfica as Estoril finished the weekend in 13th.
Third-placed Sporting Braga, meanwhile, put the disappointment of their midweek Champions League loss to Manchester United behind them through a controversial 2-0 win over Maritomo (eighth).
With both sides engaged in midweek European fixtures over the past few days, the first half was a lacklustre affair, but the match was sparked into action when Eder scored the first of his two goals in the 56th minute, firing home through a crowd of bodies after Hugo Viana's free kick was not cleared.
Braga goalkeeper Beto was forced into a series of quality saves as Maritomo went in search of an equaliser but Eder finally put the match to bed when he bundled the ball home with four minutes remaining.
Maritomo goalkeeper Romain Salin had cleared the ball on the line and claimed the goal should not count but replays indicated Eder's effort had managed to cross the line, vindicating the official's decision as Salin saw red in the melee that followed.
And, in an indication of how close this season's competition is, Rio Ave climbed from ninth to fourth on the table through a 2-1 victory over Nacional (15th).
Nacional produced an impressive first half in this encounter as Rio Ave goalkeeper Jan Oblak kept out Claudemir's spot kick in the 26th minute, although there was nothing he could do to stop Diego Barcellos opening the scoring 10 minutes later.
Joao Tomas was on hand for Rio Ave to equalise from the spot after Nacional defender Manuel da Costa brought down Braga in the box.
But despite being down to 10 men, Nacional held on until the 89th minute when Rio Ave midfielder Tarantini nodded home to give his side victory.