The Catalan side secured a priceless 1-0 win away at Dynamo Kiev courtesy of a second half goal from La Masia graduate Ansu Fati.
Barcelona are now up to second in Group E thanks to Bayern Munich's emphatic 5-2 victory over Benfica at the Allianz Arena.
So that means if the Blaugrana can achieve a victory over the Portuguese side at Camp Nou after the international break, they will qualify for the last-16 of the 2021/22 Champions League.
Victory in Kiev really was vital and it's without question the team's best result so far this season.
Barcelona had to work mighty hard for the win in the Ukrainian capital, though, so much so that members of the Spanish side attempted to resort to the dark arts in the final minutes of the game.
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As the clock ticked towards the 90th-minute, midfielder Sergio Busquets tried to halt play by feigning an injury after a clash with a Dynamo player.
The Spaniard clutched at his leg as if seriously injured, but as soon as he realised the home side were in a threatening position, the midfielder rose to his feet and carried on like nothing had happened.
Take a look at the incident here...
Video: Busquets' miraculous recovery vs Dynamo
Have some shame, Sergio.
It's far from the first time that Busquets has turned to the dark arts to try and gain an advantage for Barcelona in the Champions League.
Back in 2010, the World Cup winner used them very effectively in a semi-final encounter versus Jose Mourinho's Inter Milan side.
During the first half of that match, Busquets went down clutching his face in embarrassing fashion after a tussle with Thiago Motta, which resulted in Italian being sent off.
Video: Busquets getting Motta sent off
Inter had the last laugh that evening, though.
Despite having 10 men, Mourinho's side managed to prevent Barcelona from winning by two clear goals and secured a place in the Champions League final.