There were shocks aplenty in the Bundesliga on Friday and Saturday, though perhaps none bigger than the manner of 1. FSV Mainz 05's victory at VfL Wolfsburg. Trailing 3-0 by the half-hour mark, the visitors mounted a stunning comeback, triumphing 4-3 thanks to Ádám Szalai's late winner. FC Schalke 04 and FC Bayern München also lost, while the Serie A and Spanish Liga campaigns opened with contrasting results for AS Roma and Valencia CF respectively.
Promoted 1. FC Kaiserslautern set the tone for a weekend of Bundesliga surprises by defeating Bayern 2-0 on Friday. Ivo Iličević – who was sent off late on – and Srđan Lakić earned the hosts a first win in 11 years against the champions. Marco Kurz's team are one of five clubs on maximum points ahead of Bayer 04 Leverkusen's fixture on Sunday.
One of those, Mainz, ruined Diego's debut for Wolfsburg. The former SV Werder Bremen playmaker − who returned to Germany on Friday after a year with Juventus − put his team 3-0 up only for the visitors to embark on a remarkable comeback. Hannover 96 also have a perfect record after triumphing 2-1 at Schalke, as do Hamburger SV, for whom Ruud van Nistelrooy scored in a 3-1 defeat of Eintracht Frankfurt. Elsewhere, Marco Arnautovic struck twice as Bremen overcame 1. FC Köln 4-2.
Runners-up last season, AS Roma began their season in disappointing fashion, drawing 0-0 at home with newcomers AC Cesena. In the other game, an overhead kick from substitute Giandomenico Mesto nine minutes from time ensured Genoa CFC of a 1-0 win at Udinese Calcio.
Joaquín was the star of the show as Valencia won 3-1 at Málaga CF. The winger scored twice in the final 20 minutes, his second coming when he blasted in Aritz Aduriz's neat lay-off. Abdoulay Konko matched Joaquín's feat in the late game, his double helping Sevilla FC to a 4-1 victory against hosts Levante UD. Fernando Llorente struck the winner in Athletic Club's 1-0 success at Hercules CF.
Arsenal FC, Chelsea FC and Manchester United FC all won, though Tottenham Hotspur FC were unable to make it a clean sweep of victories for England's UEFA Champions League representatives. Andrey Arshavin scored the decisive goal as Arsenal triumphed 2-1 at Blackburn Rovers FC, while Didier Drogba's fifth goal of the fledgling season helped Chelsea – the only club with an unblemished record after three games – to a 2-0 defeat of Stoke City FC.
Following the euphoria of their qualification for the group stage, Tottenham lost 1-0 at home to a Wigan Athletic FC team which had conceded ten goals in its previous two matches. Hugo Rodallega (80) was the match-winner at White Hart Lane. United, meanwhile, eased past bottom-of-the-table West Ham United FC 3-0 thanks to efforts from Wayne Rooney, Nani and Dimitar Berbatov. West Ham, like Stoke, have yet to register a point.
Second-half strikes from Étienne Capoue and Franck Tabanou earned Toulouse FC a 2-0 win at AS Nancy-Lorraine, maintaining the southern club's 100% start to the Ligue 1 campaign. Olympique Lyonnais, however, lost for the second time in four games, 2-0 at FC Lorient, and are now eight points off the pace. Dimitri Payet struck a hat-trick in AS Saint-Etienne's 3-1 home win against RC Lens, while ten-man SM Caen's unbeaten start came to an end in a 2-0 home loss to Stade Brestois 29.
Check UEFA.com's MatchCentre for a full run down of all the weekend's domestic scores.