The LaLiga champions, who were knocked out at Anfield after letting slip a three-goal advantage from the first leg, seemed to still be struggling in the aftermath against opponents aiming for a top-four finish.
Arturo Vidal capitalised on one of the few opportunities Barca carved out in a game played at a leisurely pace, with Ernesto Valverde's men in no mood to over-exert themselves having wrapped up the title two weeks earlier.
Lionel Messi forced an own goal by Mauro Arambarri in the closing minutes to seal a result that allowed Valencia, who won at home against Deportivo Alaves, to leapfrog Getafe in the table.
Getafe had threatened to heap further misery on Barca before falling behind; Jorge Molina blazed a golden chance over the crossbar early on and while he did find the net after 25 minutes, his effort was ruled out for offside.
Barcelona created little in the final third before Ivan Rakitic had a first-time shot saved by David Soria, who could then only parry Gerard Pique's glancing header, allowing Vidal to pounce on the rebound.
Malcom should have made it two when he arrived unmarked in the penalty area but Soria saved his effort to keep the deficit down to one at the break.
The Brazilian forward missed another opportunity early in the second half, failing to convert from point-blank range after Pique's shot had bounced back into his path.
Molina hit the post as Getafe went agonisingly close to equalising before Messi powered his way into the box in the 89th minute, forcing Dakonam into a desperate sliding challenge that only deflected the ball against team-mate Arambarri and into the net.
Fourth place out of Getafe's hands
Getafe go into the final day of the season level on points with fourth-placed Valencia, who have the edge in the head-to-head record between the two sides.
Impressive Coutinho limps out
While he has found it tough going at Barca this season, Philippe Coutinho was the focal point for some of his side's best play before a knock saw him substituted midway through the second half.
