Porto edged past Guimaraes 1-0 thanks to Mehdi Taremis goal at the Estadio Dom Afonso Henriques Sunday night.
Porto reinstated a four-point-lead at the top and set a new record for invincibility in the Primeira Liga at 57 games.
In the 63rd minute, Taremi had the chance to do it all again after being taken out by Bruno Varela inside the box, but the Iranian wouldnt be as fortunate against the former Benfica keeper in a repeat of the first-half duel, missing his first spot-kick since arriving in Portugal almost three years ago.