With the top two both failing to win over the weekend, Barca knew before kick-off that a win would be vital to boost their title charge. And Hansi Flick’s men dominated throughout the first half as they went in search of the opening goal. Raphinha sent a shot inches wide of the box after he latched onto Alejandro Balde’s cutback.
But minutes later, the hosts were presented with an opportunity to take the lead after Inigo Martínez was brought down in the box by Abdul Mumin.
Following a lengthy VAR review, Robert Lewandowski buried his penalty kick for his 20th league goal of the season.
Lamine Yamal should have doubled the hosts’ lead just after the half-hour after he pounced on a loose ball in the box, but his effort was hit straight at Augusto Batalla.
In fact, Rayo took until the 37th minute before they tested Wojciech Szczesny, but the Polish stopper got a strong hand to turn Randy Nteka’s effort around the post.
The Madrid-based outfit almost stunned the Barca faithful just before the interval as Jorge de Frutos broke through the defence and finished with aplomb, but the goal was chalked off after Nteka was found to be offside and obstructing a defender.
Flick would have wanted an improvement from his side following the restart after Rayo almost drew level before half-time.
And he almost got what he wanted within 10 minutes of the second half after Pedri went onto a mazing run into the box but his cutback was dragged wide by Lewandowski.
The away side began to grow an influence in the contest and restricted their hosts for much of the second half. It took until the 71st minute for Barça to test Batalla again, as Raphinha pounced on a rebound but his goalbound effort was met by a stunning save from the goalkeeper.
The Brazilian forward was getting closer and closer after he raced through on goal but he dinked his effort over the bar. Despite the home side piling the pressure on, the second goal never arrived for Barca.
Instead, Flick had to ensue a nervy ending as Rayo came close to equalising, but the hosts held on. Victory sends the Catalans level on points with Real Madrid, while ending Rayo’s three-game winning run.
Flashscore Man of the Match: Alejandro Balde (Barcelona)