Jurgen Klopp’s side are the top scorers in this season’s competition and they showed all of their attacking prowess as Mane, Mohamed Salah and Roberto Firmino put the tie to bed before the second leg at Anfield.
Mane opened the scoring after 25 minutes with the help of some questionable goalkeeping from Jose Sa, the Porto number one diving over his low shot after a driving run from Georginio Wijnaldum.
The visitors were two ahead before the half-hour as Salah made it 30 for the season, becoming the first Liverpool player to reach that figure since Luis Suarez in 2013-14.
Liverpool’s attacking trident combined for their third goal and Mane’s second after the break, and Firmino ensured all three got on the scoresheet with 21 minutes remaining.
There was still time for Mane to complete his hat-trick and effectively end any hopes Porto had of a second-leg recovery, with Liverpool’s progression looking assured already.