Unlikely Bundesliga leaders Mainz 05 produced their most surprising win yet as they beat champions Bayern Munich 2-1 to keep their 100 percent record.
Chelsea's winning run came to an end at Manchester City in the English Premier League while Porto made it six wins out of six in Portugal.
Unfashionable Mainz 05 continued their extraordinary start by winning 2-1 at champions Bayern Munich to maintain a 100 percent record in the Bundesliga after six matches.
Hungarian Adam Szalai scored a superb goal on the turn in the 77th minute for Mainz after a freak own goal by defender Bo Svensson on the stroke of halftime had put Bayern level following Sami Allagui's 15th minute opener.
Leaders Mainz are three points ahead of Borussia Dortmund, who won 3-1 at promoted FC St Pauli. Former Real Madrid striker Raul scored his first goal of the season to give last season's runners-up Schalke 04 a 2-2 home draw with Borussia Moenchengladbach.
Real Madrid dropped from first to third after a goalless draw at promoted Levante, a result which is bound to put more pressure on coach Jose Mourinho.
Valencia won 2-0 at Sporting Gijon to go top with 13 points, one ahead of Barcelona and two ahead of Real.
Barcelona, missing the injured Lionel Messi, won a bruising match 3-1 at Athletico Bilbao, despite a sending-off for striker David Villa.
Inter Milan stayed top of Serie A despite a 1-0 defeat at AS Roma where substitute Mirko Vucinic grabbed the stoppage-time winner with a diving header.
It was the first victory of the campaign for Roma, last season's runners-up, and Rafael Benitez's first league defeat as Inter boss.
European champions Inter kept top spot on goal difference from Lazio, who won 1-0 at Chievo to end the home side's own hopes of reaching the summit five games in.
Zlatan Ibrahimovic was again on hand to give inconsistent AC Milan a 1-0 win at Genoa while Milos Krasic bagged a hat-trick, his first goals for the club, as Juventus overcame Cagliari 4-2.
An unpredictable weekend in the Premier League ended with Chelsea's lead cut to three points after their five-match winning run was ended by a 1-0 defeat at Manchester City, Argentine Carlos Tevez scoring the winner.
Arsenal failed to capitalise, losing 3-2 at home to West Bromwich Albion, while Manchester United dropped points on Sunday in a 2-2 draw at Bolton Wanderers.
Chelsea have 15 points, with United on 12 and Arsenal and City on 11. Liverpool are languishing in 16th place after a 2-2 home draw with Sunderland.
Olympique Lyon sank into a deep crisis following a 1-0 home defeat to arch-rivals and leaders St Etienne on Saturday, their first in France's fiercest derby in 16 years.
Dimitri Payet netted the only goal, also clearing off his own line twice as St Etienne remained top with 16 points from seven matches.
Lyon, 18th on five points, dropped into the relegation zone for the first time since 1995. Stade Rennes went second with a 2-1 win at Nice.
Leaders Porto kept their 100 percent record after six games with a 2-0 home win over Olhanense.
Argentina defender Nicolas Otamendi scored on his debut and Brazilian forward Hulk fired the second just before halftime.
Champions Benfica, already trailing Porto by nine points, climbed to fifth with a 1-0 away win at Maritimo thanks to a 58th-minute goal from Portugal international Fabio Coentrao.
League leaders Ajax Amsterdam came from behind twice to draw 2-2 with champions Twente Enschede while second-placed PSV Eindhoven were held to a 1-1 draw at home by Groningen.
Theo Janssen scored both goals for fourth-placed Twente but Mounir el Hamdaoui and Eyong Enoh replied for Ajax, who have a two-point lead.
Gonzalo Garcia upset PSV two minutes before time with his equaliser for third-placed Gronigen, cancelling out Ola Toivonen's effort just after the hour.
AEK Athens' disappointing start to the season continued on Sunday as Dusan Bajevic's side fell to a shock 3-1 defeat at newly-promoted Olympiakos Volos, leaving them 13th in the 16-team Super League with four points from four matches.
Olympiakos Pireaus went top with nine thanks to 3-0 win over Asteras Tripolis. Reigning champions Panathinaikos, still unbeaten, are one point behind in second after they beat Panionios 2-1.