Rayo Vallecano 0 Real Madrid 2:Real Madrid got back to winning ways in La Liga but were far from convincing in a laboured victory at their lowly city rivals on Monday.
Karim Benzema finished off a swift breakaway in the 13th minute and Xabi Alonso had to clear a Rayo effort off the line before Cristiano Ronaldo netted from the penalty spot 20 minutes from time.
The victory, only their second success in five games this season, lifted Jose Mourinho's side to seventh on seven points, eight behind leaders Barcelona, who were 2-0 winners at home to Granada on Saturday.
Real have already lost twice in La Liga, at Getafe and Sevilla, the same number of defeats the champions suffered in the whole of last season, while arch rivals Barca have won all five of their games.
Monday's match had been due to be played on Sunday night but was postponed because of alleged sabotage to the lighting at Rayo's Teresa Rivero Stadium.