Ronald Araujo headed home a Joao Cancelo corner to give the hosts the lead after 24 minutes.

However, they could have been behind in the first minute when Carlos Martin had a tap in from six yards, but goalkeeper Joan Garcia raced out to close down the angle.

That was Rayo's only shot on target in a largely uneventful first half.

Raphinha fired an effort towards the top corner but it took a deflection and Rayo goalkeeper Augusto Batalla did well to push it on to the crossbar.

After the break, Garcia produced a brilliant save to stop Unai Lopez's close-range header from drawing Rayo level.

Pacha Espino curled a shot over the bar for Rayo in the 83rd minute as Barca clung on for a vital win.

Real Madrid face rivals Atletico Madrid later on Sunday (20:00 GMT) as they look to close the gap back to four points.

Hansi Flick's side travel to Atletico after the international break on Saturday, 4 April before facing them twice more in the Champions League quarter-finals.