After mountains of prediction, speculation and analysis in the days leading up to the clash, Barcelona and Liverpool finally released their respective starting line-ups, kick-starting even more debate.
Joe Gomez in at right back for Liverpool, who would have to deal with the likes of Lionel Messi and Jordi Alba, was the first of a few interesting changes made by Jurgen Klopp. Another was his decision to bench Jordan Henderson and Roberto Firmino, trusting that Naby Keita and James Milner could get the job done.
As for Barcelona, Valverde decided that Sergi Roberto was the right man at the back, supporting the likes of Arturo Vidal in midfield, an area of the pitch that the Barça coach identified as key to disarming Liverpool's triple threat up front.
With much anticipation and a palpable tension throughout the Camp Nou, the visitors got proceedings up and running ahead of a lively five to ten minutes that followed. Neither side had a clear goal scoring opportunity but there were certainly promising signs displayed by both.
Salah and Mane began to unpick Barcelona's defence while Messi and Coutinho combined with ease to test Liverpool. The opening 20 minutes were lively but the tempo dropped temporarily while Keita received treatment for an injury which would render him out of action for the remainder of the match.
Jordan Henderson replaced Keita, taking the captain's armband from James Milner just minutes before Barcelona took the lead. The goal was doubly as painful for the visitors as it was scored by their former star, Luis Suarez.
Barcelona used the deafening Camp Nou noise to spur themselves on after the goal and Liverpool had to be careful not to let the La Liga champions get the better of them.
Despite Barcelona maintaining a dangerous level of threat and pressure in front of goal, Liverpool too were able to forge themselves a couple of decent chances with Mane's chip over Ter Stegen only just missing the target, and Mo Salah causing havoc down the right channel.
Half-time approached and a chance for both teams to continue motivating themselves with the chance at a Champions League final well within reach for both.
Liverpool absolutely flew out of the blocks after the break as James Milner claimed their clearest chance of the match. A shot which, had he put it anywhere else, would have got his side the equaliser.
Klopp's attack was supported perfectly by his defence as the likes of Matip and Gomez dealt with Jordi Alba and Messi well down the right flank. Barcelona hung on though, during an extended period of Liverpool possession and it wasn't long before they had their own opportunities to extend their lead.
Blink for just a second and things took a turn for the worst for Liverpool. Luis Suarez almost stuck the knife in deeper with his effort that clattered the post. Who should be there to pick up the rebound? None other than Lionel Messi.
Liverpool hardly had a chance to process what had just happened before Barcelona were preparing for a free kick. Lionel Messi standing over it, forebodingly. What happened next was simply out of this world.
Lionel Messi netted his 600th goal for Barcelona in mind blowing style as it sailed through the air with pinpoint accuracy as Alisson could do absolutely nothing about it. No keeper would have done for that matter. He is just simply that good.
Despite Liverpool being well and truly defeated away from home, their didn't lose hope and found themselves in front of Ter Stegen's goal with Mane and Salah who both missed sitters. Mane had his effort stopped on the line while Salah's effort from the resulting rebound clattered the post before Barcelona could clear.
Time was rapidly running out for Liverpool to clinch that all-important away goal, and the whistle eventually put an end to their misery. Only temporarily though, as Liverpool will have a considerble mountain to climb at Anfield for the second leg.
Barcelona are almost certain to secure their place in the Champions League final, unless Liverpool can exact the comeback of the season on Tuesday 7th May. If it is Barcelona in the final, they will face either Ajax or Tottenham Hotspur, whose second leg will be contested a day later.