(CNN) -- Champions Barcelona bounced back from a dismal week to return to the top of the Spanish league with a 6-1 crushing of Real Zaragoza on Sunday night.
Having dropped their first points in La Liga last weekend, Pep Guardiola's star-studded team were then surprisingly humbled 2-1 by Russian champions Rubin Kazan in the Champions League on Tuesday.
But the European champions showed no ill effects at the Nou Camp as star forwards Zlatan Ibrahimovic and Lionel Messi put on a masterclass, and unsung midfielder Seydou Keita was also to the fore with a hat-trick.
Messi, who has been criticized after indifferent recent form, set up Keita for the opener as the Mali international dived to head home the Argentine's clever cross from a well-worked short corner in the 25th minute.
Ibrahimovic smashed a fierce free-kick through the hands of Zaragoza goalkeeper Javier Lopez Vallejo four minutes later, and the big-money summer signing crossed low for Keita to score four minutes before halftime.
Keita returned the favor in the 56th minute as Ibrahimovic netted his seventh league goal of the season, before the Swede -- who also two efforts ruled out for offside -- was replaced by Bojan Krkic on 72.
The visitors pulled one back five minutes later through Jorge Lopez as Victor Valdez conceded his first goal in more than three La Liga outings.
Messi capped the win with a deft chip for his ninth goal of the season overall -- one more than Ibrahimovic -- and Keita headed his third of the night from a corner in the 86th minute as Barca moved three points clear of Real Madrid, who were held 0-0 by Sporting Gijon on Saturday.
Valencia moved up to fourth place with a 3-0 win at 10-man Almeria thanks to second-half goals from David Villa, Pablo Hernandez and Mata -- the latter two coming after home goalkeeper Diego Alves was sent off.
Villarreal won 2-1 at home to Malaga, Valladolid moved away from the relegation zone with a 4-0 win over visiting Deportivo La Coruna and Getafe beat Athletic Bilbao 2-0.
Xerez remained second from bottom after losing 1-0 at Tenerife, while Racing Santander needed a last-gasp equalizer from Manuel Arana to earn a 1-1 draw at home to Osasuna.
In Italy, Juventus moved into third place -- four points behind leaders Inter Milan -- with a 1-0 win at bottom club Siena thanks to a 72nd-minute header from striker Amauri.
Fiorentina dropped to fifth place after losing 1-0 at home to Napoli, for whom Cristian Maggio netted the only goal in the 88th minute, soon after his teammate Fabio Quagliarella saw his penalty saved by goalkeeper Sebastien Frey.
It was Walter Mazzarri's second successive win since taking over from former Italy coach Roberto Donadoni, and lifted Napoli up to eighth place.
Palermo climbed up to fourth on goal difference, beating Udinese 1-0 at home with an 87th-minute goal from Cesare Bovo.
AC Milan joined Palermo and Fiorentina on 15 points with a 2-1 win at Chievo, as defender Alessandro Nesta scored twice in the last 10 minutes
In other games, Atalanta won 3-1 at home to Parma, Lazio lost 2-0 at Bari and Cagliari continued early-season leaders Genoa's poor recent run with a 3-2 home win.
In Germany, second-placed Hamburg joined leaders Bayer Leverkusen on 22 points after being held to a 3-3 draw at Schalke.
The visitors played the last 30 minutes with 10 men after defender David Rozehnal was sent off, with striker Markus Berg scoring his second goal on 80 to put them 3-2 ahead.
But Kevin Kuranyi netted his second with a 90th-minute header to snatch a point and leave his team in fourth place, just two points off the leaders.
Werder Bremen are third on 21 points after recovering from conceding the fastest goal this season to beat Bochum 4-1.
Stanislav Sestak put the visitors ahead inside the first minute but Bremen hit back with first-half goals from Aaron Hunt and Marko Marin, while Tim Borowski and Mesut Oezil netted after the break.
Bottom club Hertha Berlin earned their first league point since the opening day of the season as they held Wolfsburg 0-0 at home, a result which left the defending champions in seventh place on 17 points.