Paris Saint-Germain were surprisingly beaten 2-1 by Montpellier in the round of 32 of the French Cup on Wednesday, while an injury to star striker Radamel Falcao overshadowed Monaco's win against minnows Chasselay.

Unbeaten at home since November 2012 and flying high at the top of Ligue 1, PSG were expected to see off a struggling Montpellier side at the Parc des Princes.

However, the visitors have improved recently under coach Rolland Courbis and took the lead 20 minutes in when Daniel Congre headed in a Siaka Tiene cross.

Home coach Laurent Blanc left Zlatan Ibrahimovic on the bench at kick-off, although that allowed Edinson Cavani to play in his favoured central striking position and the Uruguayan converted a Lucas Digne centre to draw PSG level on the half-hour.

There were chances at both ends after that but it was Montpellier who snatched a winner midway through the second half, Victor Hugo Montano heading in a corner to stun the home support.

While Montpellier had their Colombian striker to thank for taking them through, an injury to his compatriot Radamel Falcao overshadowed Monaco's 3-0 victory at Chasselay earlier.

Falcao crumbled to the ground following a challenge by Soner Ertek inside the Chasselay area – for which no penalty was given – just before the interval and needed lengthy treatment before being carried away on a stretcher.

He had given the principality club the lead just before the half-hour mark, tapping into an empty net after Valere Germain had headed down a cross for his 11th goal in French football.

Emmanuel Riviere replaced the former Atletico Madrid striker after half-time and went on to score two more goals in a game that was played at Lyon's Stade de Gerland.

The injury to Falcao and the fall-out from it somewhat marred what should have been a special occasion for fourth-tier strugglers Chasselay and their star player, veteran former Monaco captain Ludovic Giuly.

"When you play against a team from a lower division, they are going to play really hard. That's normal, and that is what I tell my players before the match but it's not possible for a referee to blow his whistle for free-kicks
without ever booking anyone," moaned Monaco coach Claudio Ranieri after the game.

"If Falcao has something serious, it is the referee's fault.

"Everyone wants to play like in England and let the game go. It's not possible here. The referee must see when there is a foul and blow his whistle."

Meanwhile, Monaco released a statement in which they said: "The player Radamel Falcao was hit in the left knee. Must await further tests in the coming days to clarify the exact nature of the injury."

Ertek himself admitted to being upset at the potential implications of his challenge.

"I am gutted. I honestly don't think I touched him," he said.

"Did he hurt his own ankle? Did I touch him accidentally? I don't know but it ruined my match."

The injury to the 60 million-euro (Ł50.4m, $82.5m) striker also stole the headlines from tiny Corsican club L'Ile-Rousse, of the fifth division, who stunned the holders Bordeaux.

In a game played in Ajaccio because their own ground was not deemed suitable for the tie, L'Ile-Rousse held out at 0-0 for 120 minutes before winning 4-3 in a penalty shoot-out.

Toulouse were also knocked out, losing 2-1 at fourth-tier Moulins, but Lyon survived a scare in their tie away to fourth-tier club Yzeure, winning 3-1 after falling behind in the 75th minute.

Yzeure, from central France, had eliminated Ligue 1 Lorient in the previous round but Jimmy Briand quickly brought the 2012 Cup winners level before a terrific Yoann Gourcuff strike put them in front and Steed Malbranque sealed the win late on.

There was considerable drama on Tuesday too as Marseille lost 5-4 at home to south-coast rivals Nice while three other Ligue 1 sides – AC Ajaccio, Sochaux and SC Bastia – all lost to second-tier opponents.

As a result, only seven Ligue 1 clubs will enter the draw for the last 16 of the competition.