The Reds became the first Premier League team to win by five goals away from home in the Champions League.
Keane stated: “When they got their first goal, it freed up their attacking players," he added. “Porto had to come at them, freed up spaces, and we have seen that the attacking players they have got are playing with great confidence and scoring goals. It was a great result for Liverpool and the tie is over.
“We talk about pace, but it quality of the pass, the movement on top of all that is pretty good to watch."
Yet despite Liverpool's sparkling Champions League win that all-but assures them of a place in the Champions League quarter-finals, Keane suggested judgement needed to be reserved over the progress being made by Klopp's side.
“Give it a bit longer," he added. “We still have to see if this Liverpool team can go on and win some trophies."
And Keane also remarked on ITV: "For a club the size of Liverpool and Tottenham…one trophy in ten years is pretty embarrassing.
“I know the Champions League has taken over now and the money behind it, but success for club like that is getting your hands on trophies.
“Clubs like Liverpool and Spurs should be able to qualify for the Champions League and win a League Cup or an FA Cup.
“These clubs with these squads should get to the knock-out stages of the Champions League and win an FA Cup or a League Cup as well. That should go hand in hand."