PARIS (AP) Manchester City showed Chelsea just how badly it wants to wrest back the Premier League title by handing the defending champion a resounding loss on Sunday.
In France, Paris Saint-Germain's title defense is off to a better start as the club moved to the top of the standings by beating promoted side Gazelec Ajaccio.
Here's a look at the top European leagues on Sunday:
The problems are piling up for Chelsea manager Jose Mourinho early in the team's Premier League title defense.
In the first heavyweight showdown of the season, Chelsea was overwhelmed in a 3-0 loss at Manchester City that could have a lasting psychological effect among the two title favorites.
Sergio Aguero scored in the first half before Vincent Kompany and Fernandinho added goals in the final 11 minutes, as City displayed the kind of attacking swagger that took them to the title in 2014.
''Today we made the complete work,'' said City manager Manuel Pellegrini, who punched the air with delight after the final whistle as a solemn-looking Mourinho headed for the tunnel.
Arsenal won its first match of the campaign by beating Crystal Palace 2-1 away, restoring confidence after a surprise 2-0 home loss to West Ham.
Paris Saint-Germain is back atop the French league standings after beating Gazelec Ajaccio 2-0 in a match pitting the biggest and smallest budgets in the division.
PSG's annual budget of 500 million euros ($555 million) dwarfs Gazelec's 14 million euros ($15.6 million), but after goals from midfielder Blaise Matuidi and center half Thiago Silva in the first 21 minutes, PSG struggled to put chances away.
PSG has six points from two matches and leads Reims and Normandy side Caen on goal difference.
Earlier, Marseille's turbulent season got worse with a 1-0 loss away to Reims, after conceding an early goal and finishing the match with 10 men.
In Sunday's other match, Lorient drew 1-1 at home to Bastia.
Bundesliga runner-up Wolfsburg started its new German league campaign with a hard-fought 2-1 win over Eintracht Frankfurt and Japan striker Yuya Osako sealed a 3-1 victory for Cologne at Stuttgart.
Osako struck in the second minute of injury time, set up by Anthony Modeste on a counterattack as Stuttgart pushed for an equalizer.
In the early game, Wolfsburg midfielder Ivan Perisic opened the scoring with a header from Max Kruse's cross in the 13th and Bas Dost made it 2-0 from close range four minutes later.
Two minutes later, former Bayer Leverkusen midfielder Stefan Reinartz scored on his league debut for Eintracht.
Defending champion Benfica routed Estoril 4-0 with a late flurry of goals to give new coach Rui Vitoria a winning home debut.
Greece striker Konstantinos Mitroglou broke through in the 74th minute by heading in a cross from Nicolas Gaitan, before Brazilian forward Jonas scored twice and Nelson Semedo polished off the win in the 89th.
Promoted club Uniao Madeira had a winning return to the topflight by beating Maritimo 2-1 in an island derby.