Rayo had suffered two crushing defeats prior to this game and although the scoreline may suggest otherwise, the home side performed remarkably well at times.
The Spanish champions ultimately proved too strong, however. Pedro opened the scoring on 31 minutes after he latched onto Lionel Messi’s pass and finished superbly, sliding the ball into the bottom corner.
The hosts had the perfect opportunity to level the game almost immediately when Adriano felled Roberto Trasharros in the penalty box, but the spot-kick was poor from the skipper and Victor Valdes easily saved.
Pedro doubled his side’s advantage two minutes after half-time when he met Cesc Fabregas’s cross and nestled the ball into the roof of the net.
And he secured his hat-trick on 73 minutes with a tap-in when Neymar unselfishly squared the ball for the winger to prod home.
Fabregas sealed the victory with 11 minutes to play when Xavi won the ball deep inside the Rayo half and found his Spanish team mate, who curled the ball into the corner of the net.