A brilliant Lionel Messi goal helped Paris Saint-Germain to a 3-1 home win over Lens on Saturday to surely end any doubt about the outcome of this season's Ligue 1 title race, after an early sending-off left the visitors with a mountain to climb.

Lens, who began the day six points behind league leaders PSG in second place, looked the better team until Ghana midfielder Salis Abdul Samed was dismissed for a dangerous challenge on Achraf Hakimi in the 19th minute.

That changed everything, and by half-time the hosts were out of sight thanks to three goals in the space of 10 minutes from Kylian Mbappe, Vitinha and then Messi, with Przemyslaw Frankowski pulling one back for Lens from a penalty.

Mbappe opened the scoring and Vitinha's long-ranger doubled PSG's lead in the 37th minute.

Both goals were good but Messi's that made it 3-0 was simply stunning, the Argentine finding a pocket out of space outside the area, feeding a pass to Mbappe and then receiving the France striker's backheel return before slotting beyond goalkeeper Brice Samba and into the far corner.

The result leaves the reigning champions nine points ahead with seven games left, meaning it is surely just a matter of time until PSG secure a French record 11th league title.

It comes at the end of a week overshadowed by allegations of racism against Christophe Galtier, the coach of the Qatar-owned club who had already been under pressure since their elimination from the Champions League last month.

Galtier said on Friday that he was "deeply shocked" by accusations that he made racist and Islamophobic remarks about Nice players when he was in charge there last season.

The allegations surfaced in an email apparently sent by former Nice sporting director Julien Fournier and which have been reported by various French media. AFP has not been able to verify the message.

PSG have given their support to Galtier who has received threats since the allegations appeared, but the affair looks set to hang over the coach and the club in the coming weeks.

Mbappe on target 

Lens were hoping to take advantage of the leaders' problems and extend a four-match winning run that had got the northern club's supporters dreaming of a first league title since 1998.

They triumphed 3-1 when the teams last met in Lens on January 1 and they started the better of the two sides at the Parc des Princes, where PSG had lost their last two games.

Yet their enterprising opening did not bring a goal and they were severely handicapped when Abdul Samed saw red for catching Hakimi with his studs above the ankle.

They were then torn apart with Mbappe firing in off the post on the turn from Vitinha's pass for his 20th league goal this season, the first for his club in more than a month.

Vitinha then smashed in his first goal in a PSG shirt before Messi took centre stage.

The Argentine's 20th club goal of the campaign was also arguably his finest in two years in a PSG shirt, just as he comes towards what may be the end of his time in France.

Lens deserve credit for regrouping in the second half and pulling a goal back when Frankowski converted from the spot after a Fabian Ruiz handball.

Belgian international Lois Openda remained a menace up front for Lens but they were left with too much to do to and will now focus on trying to hold onto a place in the top three and Champions League qualification for next season.

Marseille can move above Lens into second, and trim PSG's lead to eight points, with a win against Troyes on Sunday.

Fourth-placed Monaco will be just two points behind Lens if they beat Lorient on Sunday –- they then visit Lens next weekend.