(CNN) -- Barcelona's faltering defense of the La Liga title plumbed a fresh low Saturday with a 1-0 defeat at relegation strugglers Valladolid -- the third in the last seven league games.
No matter that Barca enjoyed 80 per cent of the possession, the only statistic that mattered was a 17th minute strike from Italian Fausto Rossi.
Arch-rivals Real Madrid can move four points clear of Barca with a home victory over Levante Sunday.
But it was Real's city neighbors Atletico who topped the standings Saturday night as a 2-0 win over Celta Vigo saw them leapfrog both the 'big two' in Spain.
David Villa scored twice to help them draw level with Real on 64 points, with a better head to head record, but having played a game more.
Barcelona will be ruing the missed opportunity to keep the pressure on leaders Real, despite boss Gerardo Martino fielding a strong team after the international break.
Lionel Messi was kept off the score sheet by excellent saves from home keeper Diego Marino and he was forced into action by the Argentina ace before the only goal of the match.
Rossi fired home from close range past Victor Valdes after indecision in the Barcelona defense.
Messi had to more efforts saved by halftime but after the break it was Neymar who missed Barca's best chance, blazing over from close range after being set up by Cesc Fabregas.
The home side held out comfortably enough and might have added to their tally when Oscar spurned a fine chance.
But they were left to celebrate a famous victory to move out of the relegation zone.
"We lacked ideas, movement and penetration, but I didn't in any way see a lack of attitude," Martino told AFP after the defeat.
His side will have to regroup ahead of the visit of Manchester City Wednesday in the Champions League, but lead 2-0 from the first leg in the last 16 tie.
The Catalan giants suffered a stinging 6-0 aggregate defeat to eventual winners Bayern Munich in the semifinals of last year's competition but had been in impeccable form under Martino until recent domestic setbacks.
Meanwhile free-scoring Bayern have continued their all-conquering form, thrashing fifth-placed Wolfsburg 6-1 in the Bundesliga Saturday, despite the match being tied 1-1 at halftime.
Bayern even trailed to a goal from Wolfsburg defender Naldo before Xherdan Shaqiri equalized by the break.
Five goals in just 17 minutes continued the incredible scoring feats of the Bavarian giants with Thomas Muller and Mario Mandzukic each getting a double.
Franck Ribery added the other for the defending German champions, who stretched their unbeaten league run to a record 49 matches.
In 24 league matches, Pep Guardiola's team have registered an impressive 72 goals to leave them 23 points clear of nearest rivals Borussia Dortmund, who play Sunday.
In France's Ligue 1, Paris Saint Germain took another big step towards retaining the title with a 3-0 win at Bastia.
Zlatan Ibrahimovic scored the opener and set up Ezequiel Lavezzi for the other two goals, the first assist from a impudent back-flick.
The win left PSG eight points clear of title rivals Monaco, who beat Sochaux 2-1 in a later game.