The Polish forward struck from close range in the first half to maintain Barcelona’s 100 percent record in the league so far this season with their seventh victory.
Barcelona dominated despite not being able to add to their lead and restored a four-point advantage over Real Madrid, who beat Alaves on Tuesday.
“You can’t always win by a lot of goals,” defender Jules Kounde told Movistar. “I think the important thing is we made a lot of chances again and took the three points… Getafe is always a tough team to handle.”
Coach Hansi Flick started Inaki Pena in goal for the stricken Marc-Andre ter Stegen, out for months with a severe knee injury, and brought Marc Casado and Alejandro Balde back into the side.
The reserve goalkeeper, who conceded 32 times in 17 matches across all competitions last season, heard his name chanted supportively by fans behind his goal and saved an early header from Carles Perez.
By contrast his opposite number David Soria’s weak touch on Kounde’s cross led to Barcelona’s opener on 19 minutes, the ball falling perfectly for Lewandowski to finish from close range.
The 36-year-old striker has seven goals in La Liga this season and leads the scoring charts, seemingly rejuvenated under Flick after struggling at times last season.
“For me, he’s the best number nine of the last 10 years,” Flick, who also coached him at Bayern Munich, told reporters. “His job is in front of the goal, in the box, and he’s doing that great.”
Teen starlet Lamine Yamal might have doubled the lead moments later when Raphinha played him in, but he nudged inches past the post.
Soria made a good save from Raphinha
Soria made a good save from Raphinha, who collected the August Player of the Month award before kick-off and soon sent another effort skidding wide.
Yamal almost bent home a delicious curling strike from a distance before the hour, but Soria tipped it over the crossbar.
The Getafe goalkeeper also palmed a dangerous Raphinha free-kick around the post as Barcelona pushed for a second to put the match to bed.
Spain’s Euro 2024 hero Yamal clipped the top of the crossbar with a vicious effort from a distance, as Barca started to grumble about Getafe’s persistently heavy challenges.
Raphinha missed a golden chance in the final stages, heading wide after a clever dart into the box but Barcelona were not punished for their profligacy.
Getafe, 19th, are still winless and wasted a fine chance of their own at the death when Borja Mayoral failed to get a shot away when well placed and free inside the box.