Hansi Flick’s side are the only team to win all four matches at the start of the campaign and moved seven points ahead of champions Real Madrid.
It was the former Leeds winger who opened the scoring in the 20th minute at the Olympic Stadium.
Striker Robert Lewandowski added a second goal just four minutes after the opener for his fourth of the season.
Valladolid kept the Catalans at bay until stoppage time in the first half, when defender Jules Kounde secured a healthy lead after prodding home from a corner.
Brazil’s Raphinha scored two in eight minutes to secure the match ball before new signing Dani Olmo added a sixth with his second goal for the club.
Substitute Ferran Torres rounded off a fantastic display from Flick’s men ahead of the international break.
