Liverpool's progression to the Champions League final was highly unlikely after last week's 3-0 defeat at Camp Nou, with the visitors needing just one goal to effectively kill the tie off.
However, you can never write Liverpool off, especially when it comes to European competition and even more so under Klopp, who has never lost a knock-out tie in Europe as Liverpool manager.
With a little over ten minutes to go, Origi netted his second to send Anfield into complete chaos and book Liverpool's place in the final for a second year running with a 4-3 aggregate win.
Liverpool were without Mohamed Salah and Roberto Firmino, but they defied all odds to display the tenacity and firepower required to dispatch Ernesto Valverde's side, all whilst stifling attacks from Lionel Messi, Luis Suarez and co at the other end.
Speaking after the game, defender Lovren discussed what manager Klopp told the players in the changing room ahead of the game.
“Congratulations to Klopp,” said Lovren, who was a substitute at Anfield on Tuesday night.
“Before the game he did an amazing speech. It was something brilliant that he did and I think he lifted us up so much.
“It was just: ‘Believe. Put it in your mind that we can do it’. It was something that we’ve never heard before.
“He said: ‘Boys, believe. One or two goals, even if we don’t score in the first 15 or 20 minutes, believe in the 65th, 66th, 67th minutes that we can score.
“Then with Anfield behind us, trust me guys, we can do it. We did it against Dortmund and we can do it tonight – just show the f*****g balls tonight.’
“And we did it!”
Liverpool's incredible performance ranks amongst their best ever in European competition, no easy feat considering the Reds' illustrious history.
The Reds face Wolves at Anfield on the last day of the Premier League season, still in with a shout of picking up a winners medal come the final whistle.
They rely on Chris Houghton's Brighton to do them a huge, albeit unlikely, favour against table-topping Manchester City, with a draw a good enough result for the Reds.
It's then three weeks to the Champions League final, where Klopp will hope to win his first piece of silverware as Reds boss against either Ajax or Tottenham.