Berbatov's nonchalant fifth-minute lob was the only goal of the Cote d'Azur derby at the Stade Louis II and the victory got Claudio Ranieri's side back on track after their shock exit from the French Cup to Guingamp at the semi-final stage on Wednesday.

A third successive league win for the principality club means they are now certain to finish in the top three and qualify for next season's Champions League.

They are eight points clear of third-placed Lille, who were held 0-0 at Marseille, and seven behind leaders PSG, who do not host Evian until Wednesday having beaten Lyon 2-1 in the League Cup final on Saturday night.

Even if PSG win that game, they will not secure a second consecutive Lige 1 championship until next weekend at the earliest.

For all the money spent last summer, finishing second would be an excellent achievement for Monaco, who were in Ligue 2 a year ago, but coach Ranieri's future has been the subject of much speculation recently.

However, the 62-year-old Italian revealed that Vadim Vasilyev, the club vice-president, had reassured him over his position after the match.

"You know what he said to me? That I will be here next season."

This win will come as a relief to him, although it will be best remembered for Berbatov's outrageous early goal.

The Bulgarian controlled a pass forward from Joao Moutinho on the left of the penalty area near the byline, looked up and nonchalantly lobbed the ball over Nice 'keeper David Ospina and into the net at the far post for his sixth goal in French football since arriving from Fulham in January.

"That was top class. I think he did it deliberately," purred Ranieri.

Monaco had chances to increase their advantage in the first half, with Valere Germain striking the post before Ospina was forced into a good save from a free-kick by his compatriot James Rodriguez.

However they couldn't get a second goal and they were fortunate not to concede an equaliser midway through the second half when Danijel Subasic saved well from substitute Dario Cvitanich and Mathieu Bodmer's header from the resulting corner was blocked by Subasic and then cleared by Mounir Obbadi right on the line.

The Nice players appealed for a goal to be given, but the officials waved play on and Claude Puel's side are without a win in five matches.

Ajaccio made the trip across Corsica for the derby against Bastia knowing they had to win to stand any chance of further postponing their inevitable relegation.

But a 2-1 loss left them 15 points from safety with only 12 points left to play for.

"We've known for a long time that we would go down so this changes nothing," Ajaccio coach Christian Bracconi said.

"We were condemned on November 14 – now it's done! We've been living with the idea for weeks. We wanted to delay it but I'm more bitter about this loss today than being relegated."

Their descent to Ligue 2 after three seasons in the topflight caused predictable delight amongst the fans of their island rivals Bastia.

While second-from bottom Valenciennes moved closer to the drop after a 6-2 drubbing by Nantes, Sochaux's hopes of surviving the drop received a huge boost with a 1-0 win at Reims.

There were angry scenes after Valenciennes' defeat, with disgruntled fans staging a protest.

Sochaux, managed since last October by Herve Renard, who led Zambia to 2012 Africa Cup of Nations glory, on 33 points, two behind French Cup finalists Guingamp, trounced 5-1 by Bordeaux with Cheik Diabate bagging a first half hat-trick.

In an afternoon when goals came thick and fast Lorient and Montpellier shared the spoils in a 4-4 draw.