• Liverpool, for all their good work, now face a mountainous task if they are to reach their second successive Champions League final.
• It was a free-kick curled into the only place Alisson could not reach from in excess of 30 yards.
Liverpool lived with Barcelona and Lionel Messi for 75 minutes of this Champions League semi-final first leg - then discovered there is a force that is simply too powerful to resist.
Jurgen Klopp's side may have trailed to Liverpool old boy Luis Suarez's first-half goal, but in all other aspects they were in control and looking like taking a very presentable result back to Anfield next week.
Indeed, a Liverpool equaliser looked a more likely outcome than further Barcelona additions as they controlled possession in the arena where it is king and pushed their opponents back into their own territory.
And then it happened.
The magic that Messi has been sprinkling on Barcelona and the entire sport for more than a decade transformed this tie in the space of those final 15 minutes. Liverpool, for all their good work, now face a mountainous task if they are to reach their second successive Champions League final.
Messi's first and Barcelona's second may have been a bundled mess after Suarez had hit the bar, but the goal that probably pushes this tie beyond Liverpool was perfection in every single respect.
It was a free-kick curled into the only place Alisson could not reach from in excess of 30 yards, Messi's 600th goal for Barcelona exactly 14 years to the day since he scored his first.
Few players could even contemplate what Messi did let alone accomplish it - and there you have the difference between the two teams.
After lengthy contemplation, some pointed a finger in Alisson's direction but this is a ridiculous assertion. This was artistic sporting perfection and any suggestion the Brazilian was somehow at fault was ludicrous.
Liverpool did not have Messi and, more significantly, the world-class marksman they possess themselves had a rare off night as Klopp's normally ruthless and clinical side found the finishing touch had deserted them.
Champions League Semi Final First Leg - FC Barcelona v Liverpool - Camp Nou, Barcelona, Spain - May 1, 2019 Barcelona's Lionel Messi celebrates scoring their third goal REUTERS/Susana VeraSadio Mane and Mo Salah have fuelled Liverpool's magnificent toe-to-toe Premier League title battle with Manchester City, but they both missed wonderful chances to secure a priceless away goal.
Of course there will be talk of famous comebacks - and Liverpool always travel with hope at Anfield - but the danger lurks in the fact if Barcelona score one (and who would seriously bet against them with Messi and Suarez to call on?), they would need five.
Liverpool got so many things right - although a gung-ho attitude could have seen them punished even further in the closing stages - and they're probably in a state of shock wondering what happened to them.
The answer is simple: Lionel Messi happened to them.
They are not the first and will not be the last, and the nightmare is they will have to go through it all again next week.
The irony was that Messi was on the margins for those 75 minutes, little flashes but often crowded out by Liverpool's strength in numbers.
Not forever though, because he rChampions League Semi Final First Leg - FC Barcelona v Liverpool - Camp Nou, Barcelona, Spain - May 1, 2019 Barcelona's Lionel Messi celebrates scoring their third goal REUTERS/Susana Veraarely is and this season Messi - as Manchester United found out in the last 16 - has made it his personal mission to return the Champions League trophy to Barcelona.
Messi, speaking in August after assuming the captaincy, revealed it was Barcelona's intention to win the Champions League this season and in his pre-match media briefing Klopp said: "That sounded already like a threat to me."
This was a threat fulfilled and inflicted on Liverpool.
Liverpool will not give this tie away and the horrendous botch Ousmane Dembele made of an open goal with the final kick of the game offers a sliver of hope, but odds against are huge.
Barcelona toiled for much of the second half but the more they toiled, the more they tried to get Messi into the game - and the man touched by greatness was there for them again. REUTERS/Susana Vera
Liverpool will look back on Mane hoisting a simple chance over the bar from Jordan Henderson in the first half, at Salah striking a post late on when it seemed easier to score after substitute Roberto Firmino had seen a shot scrambled off the line.
Where Liverpool were wasteful Barcelona were clinical. And even a team under pressure, as Barcelona were for much of the second half, still has the safety net one of the greatest players the game has ever known can provide.
Klopp gambled in playing Joe Gomez ahead of Trent Alexander-Arnold at right-back, a ploy not entirely successful as the young defender struggled, perfectly understandably as he is only just back from a broken leg, against Barcelona's attacking variation.
It leaves Liverpool with their backs against the wall at Anfield.
Is there anything that offers them belief they can somehow turn this around?
Liverpool will certainly feel they can score goals against this Barcelona defence. They had their opportunities here but contrived to waste every one.
Of course, Anfield will be a factor but that magnificent Messi free-kick has given Barcelona a massive advantage.
And for all the hope and optimism that throbs at Anfield on occasions such as we will witness in the second leg, Barcelona have Messi.
Messi is on a Champions League mission. And the evidence in the Nou Camp suggests he is in no mood to be denied.