Griezmann produced a fine finish after Lionel Messi's clever pass to open the scoring in the 33rd minute and Roberto capped a good team move six minutes later to double Barca's lead before the break.
Third-placed Getafe had earlier seen an Allan Nyom goal ruled out by VAR for a push on Samuel Umtiti in the buildup and set up a nervy ending for the hosts when Angel Rodriguez pulled a goal back in the 66th minute.
Barca's response to Nyom's disallowed goal was impressive. At that point, early in the first half, they looked second best to an in-form Getafe side. However, they got their act together and finished the half strongly, playing some of their best football since Quique Setien was appointed as coach. Every three points is so important now, too. With Madrid three points clear going into the weekend -- Los Blancos host Celta Vigo on Sunday -- they simply cannot afford to slip up as the title race heats up.
Griezmann's goal, after 500 minutes without one, should also come as a confidence boost to the Frenchman, although he did miss two good chances later in the game.
Jordi Alba was taken off with a muscle injury in the first half and is now in a race against time to be fit for away games against Napoli (Feb. 25) and Madrid (March 1) in the Champions League and La Liga, respectively. The left-back's tears in the dugout suggest he may be set for a while on the sideline, testing Barca's already-thin squad.
Once again, Barca gave up chances. Getafe had one goal chalked off and scored one after the break. A lot of Barca's problems stemmed from their own mistakes. They lost possession too easily and were caught cold on the ball more than once. Also: Messi is now four league games without a goal. Ring the alarm bells (or don't, he's still playing really well).
Manager rating out of 10
6 -- The signs of a Setien team are there, but there's still a long way to go. Not that he should be criticised -- he's been in the job for only a month, after all, and has been handed a threadbare squad.
Player ratings (1-10; 10 = best. Players introduced after 70 minutes get no rating)
GK Marc-Andre ter Stegen, 7 -- Could do little about the goal, which was a wonderful finish from Angel. Produced one moment of brilliance later to keep Getafe out, making three saves in one to stop the visitors leveling from a free kick.
DF Sergi Roberto, 6 -- Took his goal well but inefficient in attack in general. This wasn't a performance that suggests he should be picked ahead of Nelson Semedo regularly. The Portugal right-back was on the bench here after spending the week with tonsillitis.
DF Gerard Pique, 6 -- Good and bad moments. Could have been tighter to Angel on the goal and got away with a tug on him later in the game. However, late on he put out a lot of fires after sloppiness from his teammates. One challenge on Jaime Mata was particularly good.
DF Samuel Umtiti, 6 -- Really good with the ball, carrying it forward and making intelligent passes, but still looks like he could be a weakness defensively in tougher games.
DF Jordi Alba, NR -- Forced off injured with less than 20 minutes on the clock.
MF Sergio Busquets, 7 -- A couple of lapses in concentration almost cost him dearly but, in general, this was a bright performance. Intelligent on the ball and confident on the turn, he frequently bamboozled Getafe's high press.
MF Arthur Melo, 6 -- Started well but went missing as the game progressed. Needs to hit the levels he hit in the first half to keep his place in the side with Ivan Rakitic and Arturo Vidal vying for a spot in midfield, too.
MF Frenkie de Jong, 6 -- After last week's masterclass at Real Betis, this felt like a step back. Still not playing in his best position, with the coach asking him to do more in the final third than he's been accustomed to throughout his career.
FW Lionel Messi, 8 -- Bizarrely has gone four games (and over 30 shots) without a league goal, but he set up the first here and was Barca's best player once again. You lost count of the number of times he would drop one shoulder, go the other way and twist past two, three or even four Getafe defenders. The goal will come.
FW Antoine Griezmann, 7 -- Took his goal really well after a quiet opening and worked hard for the team. Also worked two really good chances in the second half, only to waste them both.
FW Ansu Fati, 7 -- A lively performance from the teenage winger, who is looking increasingly mature in his decision making despite being only 17.
DF Junior Firpo, 7 -- Replaced Jordi Alba early in the first half and went on to set up the first goal. Would have had a second assist, too, if Griezmann hadn't blazed over from close range.
MF Ivan Rakitic, 5 -- Given the final 15 minutes in place of Arthur but Barca looked better with the Brazilian on the pitch.
MF Arturo Vidal, NR -- Came on inside the final 10 minutes for Ansu.