Barcelona remain third in La Liga after a late own goal rescued a draw at Rayo Vallecano.
Trailing at the break to Unai Lopez’s stunning strike, Barca dominated the second half but missed good chances.
They finally got their reward when Florian Lejeune bundled into his own net under pressure from Robert Lewandowski.
Second-placed Real Madrid face Cadiz on Sunday while leaders Girona host Athletic Bilbao on Monday.
Barcelona made six changes from the side that came from behind to beat Alaves before the international break, with goalkeeper Marc-Andre ter Stegen absent through injury.
His replacement, Inaki Pena, looked shaky from the off and was beaten by Lopez’s ferocious right-foot effort midway through the first half.
Frustrated by a disjointed display, boss Xavi turned to former Manchester City captain Ilkay Gundogan from the bench and Barcelona dominated the second half.
However, despite taking 10 shots to Rayo’s three after the break, they still needed the help of Lejeune in the 82nd minute, as he clumsily steered the ball past his own goalkeeper with Lewandowski waiting to pounce.