UEFA Champions League Group A wrap: PSG seal top spot
Paris Saint-Germain saw off the challenge of Porto as they recorded a 2-1 victory which saw them top Group A in the Champions League.
The Ligue 1 side raced out of the blocks in the early exchanges before taking the lead thanks to Thiago Silva's powerful header.
Porto would soon equalise after a defensive lapse allowed Jackson Martinez to restore parity at the Parc des Princes on Tuesday.
The visitors would be undone by an error from goalkeeper Helton, who embarrassingly let Ezequiel Lavezzi's weak effort squirm past him.
Vitor Pereira's Porto side were patient as they searched for an opener, with Martinez denied by a last-ditch block from Silva.
PSG appeared more resolute than the side that lost meekly to Nice in Ligue 1 on Saturday, as Carlo Ancelotti's side continued testing Helton in the Porto goal.
Alex's header from a corner was well saved by the goalkeeper, before Zlatan Ibrahimovic could not quite connect with a well-worked Gregory van der Wiel corner as Porto remained defiant under pressure.
It would be just before the half-hour when the Portuguese side would finally crack.
Nicolas Otamendi's ill-timed tackle on Jeremy Menez earned him a booking, but the ramifications for his side would be far greater as Silva rose to thump home a powerful header in off the crossbar.
The lead would only last four minutes before Porto hit back on the counter-attack.
Right-back Danilo whipped in a fantastic cross which Martinez headed in after beating a static Alex to the delivery.
For all of Porto's enterprising resistance, they would once more fall behind to a calamitous error from goalkeeper Helton.
Lavezzi held off his marker before his weak shot squirmed under the goalkeeper and humiliatingly crossed the line to hand the hosts the advantage again on 61 minutes.
Pereira's men issued a response, but a glaring chance would subsequently be spurned.
Martinez was found in an open space before his chip was denied by an on-rushing Salvatore Sirigu, and former Marseille midfielder Lucho Gonzalez fired the rebound over.
Ancelotti's men held on despite wasting several chances late on through Javier Pastore and Ibrahimovic, with Porto settling for second.
In the other Group A game, Dinamo Zagreb earned a point in a 1-1 draw at home to Dynamo Kyiv after their clash at the Stadion Maksimir was delayed due to snow.
Ivan Krstanovic's last-minute penalty cancelled out Andriy Yarmolenko's opener to earn the Croatians their first point.