Andre Villas-Boas said he was confident Marseille will emerge from their turbulent run after his team slid to a third successive Ligue 1 defeat following Saturday's 3-1 loss at Monaco.

"There is no crisis. The mindset was good, the players were concentrated and focused. I think we'll come through this because the guys are giving everything," said Villas-Boas.

Nemanja Radonjic skipped clear of the home defence to give Marseille the lead on 12 minutes at the Stade Louis II, but Monaco equalised early in the second half through Guillermo Maripan's header.

Aurelien Tchouameni's first goal in the French top-flight put Monaco ahead before Stevan Jovetic's thumping free-kick in stoppage time sealed a fifth victory in six games for Niko Kovac's resurgent team.

"The goal at the start of the second half really hurt us," said Villas-Boas.

"We lost confidence. We conceded three goals from set-pieces even though we've been solid in that area. The first half was good, the second not very good."

Arkadiusz Milik made his Marseille debut off the bench after signing on an 18-month loan from Napoli, but the Polish striker was unable to arrest his new club's slump as they lost a third league game in a row for the first time since April 2015.

They remain sixth and 13 points behind leaders Paris Saint-Germain, while Monaco are closing in on the top three with just a point separating them and Lyon.

While Villas-Boas refuses to give up the fight, a tough run of fixtures threatens to plunge Marseille into deeper trouble as a return to Europe fades from view.

His side return home to face Rennes next weekend, with a second meeting against Lens in a fortnight preceding the visit of bitter rivals PSG to the Velodrome on February 7.

Villas-Boas also confirmed midfielder Morgan Sanson was set to complete a move to Aston Villa after he was left out of the squad against Monaco.

"Sanson didn't have his head in the right place to play, seeing as the club has decided to let him leave," he explained.

The 26-year-old is expected to join Villa for an initial fee of 15 million euros ($18.3 million).

Earlier on Saturday, Nice won for just the second time in 11 outings as Youcef Atal's second-half goal was enough for a 1-0 victory at Lens.