Kylian Mbappe scored on his debut for Paris St-Germain as the Ligue 1 leaders maintained their perfect start to the season with a 5-1 win at Metz.

The 18-year-old - who will cost PSG 180m euros (£165.7m) when he makes his loan move from Monaco permanent next summer - impressed throughout alongside the world's most expensive player Neymar.

But bottom-of-the-table Metz were holding their own at 1-1 until former Tottenham defender Benoit Assou-Ekotto was questionably sent off for fouling Mbappe.

That was the turning point as Mbappe then drilled home from 20 yards to put Unai Emery's side back ahead.

Neymar, Edinson Cavani's second of the game and a tap-in for substitute Lucas added some gloss to the eventual scoreline.

The defeat leaves Metz without a point this season, while champions Monaco have the chance to draw level with PSG at the top when they travel to Nice on Saturday.

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A nice problem to have

When record goalscorer Zlatan Ibrahimovic left PSG for Manchester United in 2016 after scoring 156 goals in 180 games, fans of the club may have wondered where the goals were going to come from.

That is not a problem a year on. With Neymar - a £200m signing from Barcelona - joining Mbappe and Julian Draxler behind Cavani, and Lucas, Angel di Maria, Dani Alves, Hatem Ben Arfa, Marco Verratti and Javier Pastore not even in the staring XI, Emery is not short of options.

Mbappe ended last season in electric form for Monaco and scored his first goal for France during the international break, becoming the country's youngest goalscorer in 54 years.

His PSG career started in similar fashion. He could have opened the scoring when Cavani rounded Metz goalkeeper Eiji Kawashima, with the ball running into his path, but avoided any conflict by allowing the Uruguayan to score.

He then delivered a wonderful cross from the left with the outside of his right foot which Cavani should have buried, before former Newcastle striker Emmanuel Riviere headed in after some poor defending.

Assou-Ekotto can count himself extremely unlucky to see red for a sliding tackle on Mbappe which cleanly won the ball, and his departure did for Metz. Mbappe hammered in a low shot from the edge of the area when his own ball forward was not dealt with, and the Metz defence then backed away from Neymar who curled in his fourth goal in four games from 25 yards.

Scruffy goals from Cavani and Lucas were added as the Metz defence tired. Celtic are the next team to face Mbappe, Neymar and co when they travel to Glasgow on Tuesday night.

Celtic beat Hamilton 4-1 on Friday night, with Odsonne Edouard - on loan from PSG - scoring on his debut.