The Portuguese side fought well to stay in the game in a scrappy second half to give themselves a chance of a comeback at home in next week's second leg.
Keita made his second consecutive start after scoring his first Liverpool goal against Southampton on Friday and the Guinean continued where he left off from at St. Mary's. The first half is played and now we have a bit longer than 15 minutes to prepare for the second half.
This season, Liverpool lost all their away games in the group stage of the Champions League but qualified for the knockout stage because of their impressive home form.
Once the match had finished, Liverpool fans took to social media to reflect on what they had seen, with many saluting the display of midfielder Keita, a man who so much was expected of, but who has yet to deliver on his potential at Anfield.
"We deserved the win, 100 per cent, we scored two wonderful goals and we were - in a lot of situations - really unsafe, on the right side especially with Mo, Hendo and Trent, the crosses and the passes".
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Henderson has played 316 times for Liverpool since joining from Sunderland in 2011 and replaced club legend Steven Gerrard as captain in 2015.
There were edgy moments for Liverpool - one in the first-half when Alisson tipped away a deflected cross with the ball finding the arm of Alexander Arnold in the box.
"Overall it was a really good performance".
If Liverpool is at all caught up in thinking about winning the tie in the first leg, that's where Porto may spoil the party.
Liverpool came out firing immediately after the break and thought they had a third when Mane found the back of the net after taking down an inch-perfect Henderson pass, only to be flagged offside. "Porto will try everything to strike back and that will be a really tough game again".
"We gave little situations away where the striker had the chance to finish in one-on-ones, but we didn't give a lot away".
With a comfortable Champions League quarter-final first-leg victory in the bank, Liverpool's players returned to Melwood on Thursday and turned their attention to Sunday's Premier League clash with Chelsea.