LONDON — Everything had been going right for Inter Milan, with five consecutive victories, just one goal conceded and the undisputed top slot in Serie A.
Until Sunday, that is.
Then it all unraveled in front of a disbelieving home crowd at San Siro as Inter conceded three goals before the first 25 minutes were up, and went on to lose 4-1 to Fiorentina.
The Florence club now leads the standings for the first time since 1999.
Paris Saint-Germain finished the weekend four points clear in France after second-placed Saint-Etienne met with the same fate as Inter, losing 4-1 at home to Nice on Sunday.
In Spain, Deportivo La Coruna kept pace with league leaders Villarreal by beating Espanyol 3-0, with the country's five Champions League contenders having played on Saturday.
In the day's only match of the English Premier League, Crystal Palace continued its promising start to the season by beating Watford 1-0 away to move up to sixth in the standings.
Here is a look at Europe's major leagues:
Inter Milan's perfect record this season was left in tatters after Fiorentina triumphed 4-1 at San Siro to move top of Serie A.
Inter had only conceded one goal in its first five Serie A matches but found itself 3-0 down after 23 minutes in a nightmare first half for the home side, which also had Joao Miranda sent off in the 31st minute.
Inter and Fiorentina both have 15 points, two more than Torino after it held on for a 2-1 win over Palermo despite ending the match with nine men.
Sassuolo, which drew 1-1 against Chievo Verona, is a point further back. Lazio also has 12 points after the capital side came from behind with 10 men to win 2-1 at Hellas Verona for the first time in 24 years.
Udinese also came from behind to win by the same scoreline at Bologna, ending a four-match losing streak, while 10-man AC Milan lost 1-0 at Genoa.
Striker Lucas Perez scored a goal in each half to help Deportivo La Coruna defeat Espanyol 3-0 and move closer to the leaders in the Spanish league.
Deportivo went ahead with an own goal by Espanyol defender Alvaro Gonzalez in the 14th minute, and Perez made it 2-0 after a fast breakaway in the 27th and added a third from inside the area in the 49th. They were Perez's third and fourth goals this season, leaving him only one behind league leaders Karim Benzema and Cristiano Ronaldo.
"We needed this victory for the fans and to keep the team headed in the right direction," Perez said.
It was Deportivo's third win in six matches, enough to keep it within range of first-place Villarreal and the rest of the teams crowding the top of the table at the start of the season. Deportivo has one point more than Barcelona and two more than Real Madrid and Celta Vigo
Also Sunday, Real Betis came from behind to earn a 2-1 win at Sporting Gijon, Getafe defeated Levante 3-0 at home and Real Sociedad drew 0-0 with Athletic Bilbao in the Basque derby.
Saint-Etienne missed the chance to close the gap on French league leader Paris Saint-Germain as it fell to a surprise 4-1 defeat at home to a Nice side which ended the match with nine men.
Hatem Ben Arfa scored two stunning goals for Nice after Saint-Etienne defender Loic Perrin had cancelled out Vincent Koziello's fifth-minute opener.
Jean-Michael Seri scored Nice's other goal before teammates Nampalys Mendy and Maxime Le Marchand were dismissed in separate incidents.
Jean-Christophe Bahebeck missed a late penalty for Saint-Etienne, which remained four points behind PSG after the three-time defending champion's victory at Nantes on Saturday.
Earlier, Marseille's miserable start to the season continued with a 2-1 home defeat to Angers. Montpellier beat Lorient 2-1 and last year's runner-up Monaco was held 3-3 at Guingamp.
GERMANY Darmstadt captain Aytac Sulu equalized in the last minute to earn the promoted side an unlikely 2-2 draw at Borussia Dortmund in the Bundesliga.
Sulu struck after Florian Jungwirth's initial effort was blocked to leave second-place Dortmund trailing league leader Bayern Munich by four points before the two sides meet in Munich next weekend.
"We've had two very unnecessary point-losses one after another," said Dortmund defender Mats Hummels, referring to his side's previous draw with Hoffenheim. Dortmund had won its opening five games.
Darmstadt stunned the home side in the 17th minute when Jerome Gondorf floated a precise cross for Marcel Heller to smash a volley into the far corner. Pierre-Emerick Aubameyang equalized in the 63rd from close range and claimed his second in the 71st, running onto Adnan Januzaj's through ball before shooting inside the far post.