The weekend's opening matches in the Bundesliga and Ligue 1 threw up the customary collection of first-day shocks and unexpected results.
Borussia Dortmund may have launched their German title defence by slickly dismantling Hamburg 3-1 on Friday evening, but a blunder from new recruit Manuel Neuer saw Bayern Munich beaten 1-0 at home by Borussia Monchengladbach and there were also defeats for last season's runners-up Bayer Leverkusen and Champions League semi-finalists Schalke.
In France, title holders Lille and 2010 champions Marseille were both held to draws, and the Qatar Sports Investments era at Paris Saint-Germain opened with the dampest of damp squibs as Antoine Kombouaré's hastily assembled side crashed 1-0 against Lorient at a rain-soaked Parc des Princes.
Mathematically, a defeat on the first day of the season is no more damaging than a defeat that falls at any other moment in the campaign, but nothing kills pre-season optimism quite as abruptly as a first-day reverse. So how gravely does an opening-day loss undermine a team's chances of winning the league? A look at recent history suggests that, although such defeats are usually fatal, there are remarkable exceptions.
In the past 20 seasons, only 11 teams have managed to win one of the five major European leagues after suffering defeat on the opening day of the season: Manchester United (1992-93 and 1995-96), Barcelona (2008-09), Stuttgart (1991-92 and 2006-07), Borussia Dortmund (2010-11), Paris Saint-Germain (1993-94), Auxerre (1995-96), Nantes (2000-01) and Lyon (2001-02 and 2003-04). Serie A is the least forgiving championship, and by some distance: a 1-0 loss for Torino at Bologna on October 5, 1975 represents the last time an Italian side who went on to claim the title lost their opening league match.
Discounting the 1992-93 Ligue 1 season and the 2004-05 Serie A campaign (which saw Marseille and Juventus stripped of their respective league titles), the winners of Europe's top five leagues over the last 20 years have won 63 per cent of their opening matches, drawn 26 per cent and lost just 11 per cent. Opening-day defeats are clearly costly, but both Bayern and PSG may find solace in the fact that such setbacks occasionally prove to be springboards for astonishing runs of success.
Manchester United began the inaugural Premier League campaign in 1992-93 with a 2-1 defeat by Sheffield United at Bramall Lane and found themselves in the relegation zone two games later after a 3-0 loss at home to Everton followed by a 1-1 draw with Ipswich Town. However, 10 months on United were crowned English champions for the first time since 1967 (and they've not done badly since).
Likewise, few will recall that Lyon's unprecedented streak of consecutive Ligue 1 titles began with an unremarkable 2-0 defeat at Lens in July 2001. Juninho Pernambucano made his league debut in the Lyon midfield that day and the Brazilian cannot have imagined that when he left the club eight years later he would do so with seven league winners' medals in his collection.
More recently, Barcelona constructed their unforgettable 2008-09 Treble triumph on the creaky foundations of a 1-0 loss at newly promoted Numancia in August 2008, in what was Pep Guardiola's first competitive game in charge. "This is a long process and we wanted to start well but we have not," said Guardiola at the time. "We now have to go on and improve and do better."
Kombouaré and Bayern coach Jupp Heynckes reacted in similar fashion to their teams' setbacks over the weekend - Heynckes urging his troops to "stay calm and keep working", Kombouaré asserting that PSG "mustn't panic". Such apparently formulaic post-match comments are easy to dismiss as hollow platitudes, but the examples of United, Lyon and Barcelona demonstrate that first impressions can often be deeply misleading.