Benfica remain three points clear of title rivals Porto with four Primeira Liga games to go after the two Portuguese giants played out a 0-0 O Classico draw at Estadio da Luz on Sunday.
Having lost 2-0 at home to their bitter rivals earlier in the season, Julen Lopetegui's Porto needed a comprehensive victory in order to claim the head-to-head advantage, but they were met by a resolute and determined Benfica.
Despite the pre-match billing and the typical importance of the contest, the first half passed with few talking points, as the two teams managed just a single shot between them in a thoroughly disappointing opening 45 minutes.
Although the match improved as a spectacle after the break, the deadlock remained, as Talisca headed wide for Benfica in the 55th minute, before Oliver Torres' low cross agonisingly missed Porto striker Jackson Martinez soon after.
Ricardo Quaresma's introduction from the bench injected excitement, but it was the hosts who should have snatched all three points 10 minutes from the end, Ljubomir Fejsa smashing over from eight yards.
Ultimately neither side could find the breakthrough and Lopetegui's frustrations threatened to get the better of him as an embrace with Benfica coach Jorge Jesus turned into an ill-tempered exchange following the full-time whistle.
In Sunday's two earlier matches, Pacos Ferreira boosted their slim hopes of a top-five finish with a 3-1 win at Arouca, while rock-bottom Penafiel lost for the 20th time this season, as Nacional ran out 2-0 victors in Funchal.
