Paris Saint-Germain clinched the French league title for the second successive season on Wednesday before going down to a 2-1 home defeat against Rennes at the Parc des Princes.
Confirmation that PSG had secured the Ligue 1 championship came through just before they kicked off their match as it emerged that nearest challengers Monaco had been held to a 1-1 draw by Guingamp, and news of the result in the principality was met with jubilation by Paris fans.
The result left second-placed Monaco seven points behind PSG with only two matches of the season remaining and means that Claudio Ranieri's side will have to settle for the runners-up spot and automatic Champions League qualification.
However, PSG captain Thiago Silva admitted that it was a rather strange way for his team to win the title.
"There is no sadness but it was a difficult match," the Brazilian defender told Canal Plus television.
"We did well for 10 months. The last month has not been good but I am very happy today. I hope we can continue like this next season and try to win the Champions League as well," he added.
Monaco took the lead against Guingamp in the 77th minute courtesy of a strike from the in-form Dimitar Berbatov, his fifth in his last four games.
However, Fatih Atik equalised for the Bretons five minutes from the end, and PSG fans cheered as it filtered through to them that Monaco had been pegged back.
Guingamp, who won the French Cup by beating Rennes 2-0 in the final at the weekend, hung on for a precious draw in their fight against relegation despite having Moustapha Diallo sent off.
- Ibrahimovic makes comeback -
PSG appeared buoyant at the start of their match and took the lead inside three minutes when Edinson Cavani found Ezequiel Lavezzi, who drilled home.
However, Rennes recovered to equalise midway through the first half, on-loan Marseille winger Foued Kadir firing into the net through a crowd of bodies in the PSG box.
Paul-Georges Ntep set up that goal, and four minutes later the France under-21 forward put Rennes in front, his free-kick from wide on the left avoiding everyone in the box as it sailed into the net at the far post.
That proved to be the end of the scoring, with the home side unable to conjure an equaliser even after the introduction of Zlatan Ibrahimovic just before the hour mark, the Swede making his first appearance in a month after a thigh injury.
Remarkably, it was PSG's first home league defeat in 30 matches since a nine-man Rennes side also won 2-1 at the Parc des Princes in November 2012, and the result leaves Rennes safe from the threat of relegation.
"I expected a reaction after the Cup final, but maybe not as much as a win away to Paris," admitted Rennes coach Philippe Montanier, whose side are now six points clear of the drop zone and with a far superior goal difference.
"After the final it was very difficult, but there is a unity amongst the squad and the club as a whole that allowed us to come through it. We needed the points and to secure our survival here is a huge satisfaction."
Paris have toiled in the league ever since being knocked out of the Champions League by Chelsea last month, with this defeat following a loss at Lyon and a 1-1 draw at Sochaux 10 days ago.
However, their dominance of Ligue 1 was previously absolute, and they have not been off the top of the table since October.
Helped by Ibrahimovic's tally of 25 goals, they have already set a new record for the most goals scored in a Ligue 1 campaign and are on course to break the record for the most points.
Despite losing to Rennes, PSG have 83 points with two matches left, one fewer than the all-time best mark, set by Lyon in the 2005-06 season.
It is PSG's fourth French title since their foundation in 1970, following previous triumphs in 1986, 1994 and last season, and is added to the League Cup they won last month by beating Lyon 2-1 in the final.