Jurgen Klopp’s side were superb throughout as they maintained their 100% start in the competition.
Mohamed Salah’s prodded finish set them on their way at the Estadio do Dragao, which once again proved a happy hunting ground.
And with memories of 4-1 and 5-0 victories in recent campaigns fresh in the mind they delivered a performance brimming with pace, precision and energy.
Sadio Mane extended their lead on the stroke of half-time with a back-post tap in and with the Reds wearing black armbands to mourn the death of Roger Hunt, fittingly Salah – their modern-day equivalent – contributed his second with a clinical finish into the bottom right corner.
Mehdi Taremi’s header briefly gave the hosts heart but Roberto Firmino added the fourth for Liverpool with home goalkeeper Diogo Costa stranded after woefully charging up the pitch to attempt to clear.
And the Brazilian rounded off a comprehensive victory late on after pouncing on a rebound from Curtis Jones’ volley.
In Tuesday’s other Group B fixture Luis Suarez scored a stoppage-time penalty as Atletico Madrid won 2-1 at AC Milan.
Porto and their manager Sergio Conceicao must be weary of hosting Liverpool in this competition.
The Portuguese side have now conceded 14 goals in Liverpool’s last three visits to the Iberian Peninsula though they contributed to their own downfall in part with 22-year-old goalkeeper Costa culpable for two if not three of the Reds’ goals.
Porto were also hampered by the loss of veteran defender Pepe and his wiles in the warm-up, while midfielder Otavio limped off early on with the score at 0-0.
And while Porto attempted to press Liverpool, whenever possible they were too often carved open by the slick football on display from Klopp’s side.
It was the sort of display that if produced later in the competition would mark the Reds out as potential winners, and it was heavily influenced from midfield.
Jordan Henderson making his 400th appearance for the visitors was excellent, demanding the ball at every opportunity and combining his defensive duties with some intelligent passing and movement to set Liverpool on the attack.
But even he was overshadowed by 20-year-old Jones, who was involved in four of Liverpool’s five goals and aside from central defenders Virgil van Dijk and Joel Matip played more passes (72) than any other visiting player.
Jones’ change of pace allowed him to get a shot that diverted to Salah for the first and he showed wonderful presence of mind to slide in the Egyptian for his second.
And it was his ball forward that caused confusion and embarrassment in the Porto defence for the first of Firmino’s two goals.