Arda Guler scored a first-half goal for Madrid, who moved back within four points of Barcelona. The Catalan club edged Mallorca 1-0 on Tuesday.
Madrid coach Carlo Ancelotti used many reserves ahead of Saturday's Copa final in Seville. Brazil forward Endrick made his first Spanish league start with the club, Vinicius Junior was substituted in the second half. and Jude Bellingham came off the bench in the second 45.
Midfielder Eduardo Camavinga had to be replaced with an apparent muscle injury in the final minutes and is in doubt for Saturday's final.
Madrid had demoralising losses in both "clasicos" against Barcelona this season — 5-2 in the Spanish Super Cup final and 4-0 in their first league encounter at the Santiago Bernabeu.
Guler scored the winner with a well-placed right-footed shot in the 21st minute at the Coliseum in Getafe, while goalkeeper Thibaut Courtois needed to make a couple of difficult saves late to secure victory.
It was the third league win in a row for Madrid, who endured a Champions League elimination against Arsenal in the competition's quarter-finals.
Getafe have lost three in a row, and four of their last five league games, to sit in 12th place.
Elsewhere on Wednesday night, Celta Vigo moved to seventh by routing fifth-placed Villarreal 3-0 at home.
Villarreal played a man down from the 37th minute after Eric Bailly was sent off with a straight red card.
Inaki Williams scored five minutes into the match to give fourth-placed Athletic Bilbao a 1-0 win over 18th-placed Las Palmas, helping the Basque Country club to open an eight-point gap above Villarreal.
Alaves moved out of the relegation zone by beating ninth-placed Real Sociedad 1-0 at home with a 65th-minute goal by Nahuel Tenaglia.
25°C