Barcelona saw out a nervy win against Rayo Vallecano to return to the top of La Liga for the first time since December.

Robert Lewandowski's first-half penalty was enough for Barca to leapfrog title rivals Real Madrid and Atletico Madrid, after both capital clubs dropped points in 1-1 draws on Saturday.

The Poland striker rolled his spot-kick in off the post - his 20th league goal of the season - after the hosts were awarded a contentious penalty following a video assistant referee (VAR) review.

Rayo midfielder Pathe Ciss was penalised for pulling down Inigo Martinez in the box, though the Barcelona centre-back was never close to getting to the ball ahead of goalkeeper Augusto Batalla.

The visitors were incensed when they were denied a penalty following a similar incident, this time Ciss going to ground.

The controversy continued as Rayo thought they had equalised when Jorge de Frutos latched on to a through ball and finished past Wojciech Szczesny, but striker Randy Nteka - standing in an offside position - was judged to have interfered with Martinez's ability to make a tackle.

Barcelona spurned several chances to score in the second half, and were fortunate not to concede a late equaliser when De Frutos headed over following a Rayo counter-attack.

Hansi Flick's side go top of the table with 51 points, ahead of Real Madrid on goal difference, and one point above Atletico, with 14 games left to play.