Pedro Rodriguez scored three goals and Victor Valdes saved another penalty in Barcelona's 4-0 win at Rayo Vallecano on Saturday, keeping the defending Spanish league champions perfect through five rounds.
Pedro scored from a pass by Lionel Messi in the 33rd minute and added two more goals in the 47th and 72nd after Valdes saved his second penalty in four days following his stop in Wednesday's 4-0 over Ajax in the Champions League.
The Spain forward has five goals this season, making him the league's second-leading scorer behind Messi with six.
Cesc Fabregas capped the rout in the 80th with Rayo searching for a consolation goal.
"We knew the difficulties Vallecas Stadium presents, it's a tough ground to win at," Pedro said after his first career hat trick for Barcelona. "They have a competitive team, but we were able to find the spaces we needed to score."
Atletico Madrid also got its fifth win in as many rounds to lie level on points with Barcelona after a no-nonsense 2-0 win at Valladolid.
Atletico's defence limited Valladolid to one shot on goal while midfielder Raul Garcia and forward Diego Costa both scored goals set up by Jorge "Koke" Resurreccion in the second half.
Moments after goalkeeper Diego Marino saved his header, Garcia scored in the 56th with a no-look header from Koke's cross that Marino could only watch float over him and into the net.
Koke then lobbed a delicate through ball down the middle of pitch for Diego Costa to seal the result in the 72nd.
Barcelona's and Atletico's victories gave them an overnight five-point advantage over Real Madrid before it hosts Getafe on Sunday. Atletico visits Madrid next round in their first meeting since Atletico beat Madrid in the Copa del Rey final last season.
Encouraged by its raucous fans, Rayo set a brutal pace from the start, and Valdes was called into action in the third minute to turn back Alberto Perea's header.
"Valdes is having an exceptional run," said Barcelona coach Gerardo Martino. "He's among the three best goalkeepers in Spain. It's my turn to enjoy having him as my player, even though you don't always want to see your goalkeeper having to make three or four decisive saves."
Barcelona matched Rayo's intense pressure and a ball stolen by Alex Song led to Barcelona's opener. Messi took the ball, drew in the hosts' defence, and laid off for Pedro arriving down the right side to drive a low shot into the net.
It was then Valdes' turn to shine again this season, his last with the Catalan club which he seems determined to make his best.
Rayo was poised to level in the 35th when Barcelona defender Adriano fouled midfielder Roberto Trashorras in the area, but Valdes stood firm and had little trouble parrying Trashorras' spot kick.
"In the first half our team was able to cause Barcelona problems," said Trashorras. "If I had scored that penalty, they would have had even more trouble. Having studied him I thought that Valdes was going to dive to one side, and I tried to shoot down the middle since he had gone to one side the other day. But he did well to wait."
Pedro scored his second goal when he raced in to stab Fabregas' cross home after the former Arsenal midfielder forced Rayo into losing the ball deep in its own half.
Barcelona's Neymar provided constant danger throughout the match and came close to his first goal in league play with a shot off the post in the 66th. The Brazil striker has already made his mark by giving defences fits and leads the league in fouls received.
As Rayo's players tired while its fans continued to urge them forward, Neymar started and extended a flowing move by squaring for Pedro to tap in his third goal before Fabregas took the fourth.
Also, Real Sociedad's scoring drought reached three games when Malaga held the Basque club to 0-0 at home, while Levante rallied to 2-2 at 10-man Almeria.
Sociedad, which lost its Champions League group opener on Tuesday, increased its winless run in the domestic competition to four rounds.
Despite selling several players this summer, first-year coach Bernd Schuster has Malaga on a three-game unbeaten streak.
The promoted Almeria remained winless through five rounds after squandering a second-half lead for the fourth time this season.
Also on Sunday, it's: Real Betis vs. Granada, Celta Vigo vs. Villarreal, and Valencia vs. Sevilla. Espanyol hosts Athletic Bilbao on Monday.