PSG struggled to create any early chances against Metz, which has the worst defensive record in the league this season, conceding 34 goals in its 15 previous games, but finally found a way through in the 31st minute.

Lee Kang-in played a one-two from a short corner before floating the ball towards the six-yard area where Ramos steered his header into the bottom corner.

PSG scored its second eight minutes later. Ibrahim Mbaye played a pinpoint pass across the box for Ndjantou to slide in and net his first goal for the club. The 18-year-old became PSG's 17th different goalscorer in Ligue 1 this campaign.

Ramos wasted a gilt-edged chance to score another goal minutes earlier when his touch let him down as he tried to round the keeper and, out of nowhere, three minutes before the break Metz pulled one back.

Habib Diallo had a shot blocked in the box and when the ball came out to Jessy Deminguet he smacked a half-volley into the roof of the net to set up a more intriguing second half.

Metz keeper Jonathan Fischer denied Ndjantou, Ramos and Lee as PSG looked to kill off any hopes of a Metz comeback after half-time but the hosts almost found an equaliser before the hour mark.

Diallo volleyed narrowly wide and moments later, PSG goalkeeper Matvey Safonov got down well to parry away a Koffi Kouao strike.

But, just when the hosts were enjoying their best period, PSG launched a counter-attack from the resulting corner, which sent substitute Doue through on goal and he made no mistake with a composed finish in the 63rd minute.

Mbaye's shot rocked the crossbar as PSG began to turn the screw and Fischer made another fine save from Doue's ferocious strike.

Metz refused to bow and nine minutes from time the home side created a beautiful goal to set up a nervy ending for the visitors.

Giorgi Tsitaishvili made a bursting run with the ball into the box from the wing and although he momentarily lost possession, Gauthier Hein played a clever backheeled pass back to Tsitaishvili, who rifled his shot into the far corner.

PSG held on, but Metz will take satisfaction from its performance and if it can produce this type of display against lesser sides, it might be able to avoid a swift return to Ligue 2.

PSG is on 36 points, two ahead of Lens, which hosts Nice on Monday (AEDT) while Metz remains bottom of the standings with 11 points.