Ferran Torres wasted two early chances as he twice missed the target when well placed, but Barca did take the lead when Bernal fired into an empty net after Lamine Yamal left two Atleti defenders for dead and delivered a low ball across the six-yard box.
The visitors rarely posed an attacking threat, though Ademola Lookman really should have done better when presented with a headed opportunity late in the first half. And he was made to pay moments later when Pedri was felled in the box and Raphinha stepped up to score from the penalty spot with the final kick before half-time.
With renewed belief Barca went in search of more goals, and Joao Cancelo and Bernal both forced Juan Musso into saves from the edge of the box. Those two players eventually combined for Barca's third goal, as Cancelo's searching cross was volleyed home by Bernal at the back post.
Wave after wave of Barcelona attack followed, but they could not test Musso in the Atletico goal, with Gerard Martin's strike that sailed over the bar the closest they came to an equaliser in the tie. Instead, it will be Atletico who play Real Sociedad or Athletic Club in April's final.
GOAL rates Barca's players from Camp Nou...
