Leading 2-0 from the first leg at Anfield, goals from Sadio Mane, Mohamed Salah, Roberto Firmino and Virgil van Dijk underscored an accomplished performance by Jurgen Klopp’s side.
The Reds had been forced to survive an early bombardment in the saturated Estadio do Dragao, before Mane opened the scoring with a sliding effort – from Salah’s scuffed shot – which was confirmed by VAR.
Salah stroked in a second after the break from a superb counter-attack before Real Madrid-bound defender Eder Militao pulled a goal back for the hosts.
Liverpool reasserted their authority though with close-range headers from Firmino and Van Dijk sealing an impressive victory.
Remarkably Porto had looked capable of capitalising on a sluggish Liverpool start until Mane’s goal swung the momentum of the second leg back in the visitors’ favour.
Until then Liverpool were the beneficiaries of errant finishing from the home side – with Moussa Marega notably failing to convert any of his five chances in the opening 20 minutes.
Liverpool will face Barca – who beat Manchester United in the last eight – in the first leg of their semi-final at the Nou Camp on Tuesday 30 April (20:00 BST).
Mane, Salah and Firmino were all scorers when Liverpool thrashed Porto 5-0 in their last-16 tie at this venue in February 2018.
And like in that game, the Reds’ attacking triumvirate were again on the mark in another emphatic win that was underpinned by the clinical nature of their finishing.
Senegalese forward Mane’s anticipation brought Liverpool’s opener, with his 22nd goal of the season ensuring he is already two goals better off than his tally in 2017-18.
Mane and Salah’s goals arrived with the Reds’ first two efforts on target – with Salah’s strike in particular highlighting the threat Klopp’s side pose when they break with speed.
Firmino and Trent Alexander-Arnold were both involved before Salah took a touch to control the full-back’s pass and then dispatched a left-foot shot past three-time Champions League winner Iker Casillas.
While Liverpool impressed in attack with Firmino heading home the third, the strides they have made in defence were also key against relentless opponents.
Klopp paid out over £140m on Netherlands defender Van Dijk and Brazil goalkeeper Alisson to strengthen the spine of his team, and the duo again proved their worth.
Van Dijk excelled, making nine clearances – more than any other player – before his late goal, while Alisson’s positioning enabled him to gather several Porto attempts on goal with the minimum fuss.
