Jaime Mata's 56th-minute penalty was enough for Getafe to secure a first league win over Barcelona since November 2011.
Ronald Koeman suffered the first defeat of his reign as Barcelona failed to capitalise on a shock loss for Real Madrid, slipping to a 1-0 defeat at Getafe.
With El Clasico looming on the horizon, reigning champions Madrid were stunned by newly promoted Cadiz as LaLiga resumed on Saturday following the international break.
However, Barca missed the chance to move level on points with their rivals ahead of next Saturday's showdown at Camp Nou.
Jaime Mata's 56th-minute penalty was enough for Getafe to secure a first league win over their illustrious opponents since a similar 1-0 result back in November 2011, a run of 16 games.
Lionel Messi struck a post and Getafe captain Djene Dakonam was spared from scoring an own goal by the crossbar, but - after starting his reign with back-to-back wins - Koeman has now seen his side pick up a solitary point from their next two outings, laying bare the size of the task on his hands.