World Cup star Kylian Mbappe's lethal finishing and confusing VAR decisions helped Paris Saint-Germain to a second straight win at the start of its French title defense.
Mbappe came off the bench to score twice in a 3-1 win at Guingamp on Saturday but the victory was overshadowed by a contentious VAR decision in PSG's favor, and a seemingly clear penalty not given to Guingamp with the scores level.
"It's true I added something," Mbappe said. "But the whole team wanted to change things after the first half."
PSG trailed 1-0 at halftime, which could have been 2-0 only for referee Clement Turpin to be alerted by the video assistant referee as to a possible foul in the buildup to a goal. He disallowed the header by midfielder Nicolas Benezet.
Guingamp president Bertrand Desplat was furious.
"Above all, I'll say it wasn't a great night for video refereeing," Desplat said. "You can see there's an enormous amount of progress to be made and French refereeing will have to get quickly up to speed, because you can't ruin great evenings like this."
There was not much Guingamp could do against Mbappe, however.
The 19-year-old forward, who helped France win the World Cup last month , came on at halftime and instantly sparked PSG's attack.
Eight minutes later, Neymar's trickery with the ball led to him earning a penalty, which he took himself for 1-1.
But with about 10 minutes left, PSG defender Thomas Meunier clattered into Guingamp winger Marcus Coco as he charged into the area.
Although Meunier sent Coco tumbling heavily, Turpin did not give the penalty and — more surprisingly — VAR officials did not alert him to review the incident.
"I don't understand it at all ... I think it at least deserved to be checked by the referee," Desplat said. "The VARs (video assistant referees) were completely inadequate."
Two minutes later, the clinical Mbappe put PSG ahead and then finished off Guingamp in the 90th minute.
He curled his first into the bottom corner and deftly chipped the second over the goalkeeper from close range.
Just like in last weekend's 3-0 win against Caen, coach Thomas Tuchel again started three of PSG's youth academy players, with 19-year-old Colin Dagba at center half, 19-year-old Antoine Bernede in midfield and 18-year-old U.S. international Timothy Weah in attack.
But they struggled as Guingamp, a small town in Brittany, dominated the first half.
VAR AND VETERANS
PSG goalkeeper Gianluigi Buffon made a sensational early save from striker Nolan Roux's close-range shot. Buffon looked beaten as he dived to his left but the 40-year-old Italian showed incredible reflexes to stick out his right hand and push the ball onto the crossbar.
But Guingamp scored in the 20th minute, with Dagba's mistake leading to Roux's 70th top-flight career goal.
Dagba chested the ball and then, thinking center half partner Thiago Silva was coming across to cover, he hesitated. Coco sprinted into the gap and squared the ball to Roux.
Buffon was beaten again five minutes later when Coco flicked the ball from the left to Benezet, who headed in. Turpin went for a video review after being alerted by VAR officials. He disallowed it because of an apparent trip by Benezet on Dagba as they contested the ball, although there appeared to be only minimal contact at most.
FATHERS AND SONS
Weah, the son of current Liberia President and former PSG striker George Weah, made way for Mbappe.
Teenagers Weah and Mbappe combined are three years younger than Buffon — who hugged Guingamp striker Marcus Thuram after the game.
Buffon was teammates with his father, the robust defender Lilian Thuram, at Italian side Parma — the city where Marcus was born in 1997.
Radamel Falcao had a penalty saved as Monaco drew 0-0 at home to Lille.
Dijon joined PSG on six points after beating Nantes 2-0 at home. Striker Julio Tavares thought he had a chance for a hat trick from the penalty spot, but a VAR decision awarded a free kick instead.
Winger Ismaila Sarr scored a spectacular goal as Rennes won 1-0 at home to Angers, while Montpellier midfielder Florent Mollet scored with a powerful drive and created the other goal in a 2-1 win at Amiens.
Former France and Arsenal midfielder Patrick Vieira's Nice side drew 1-1 at Caen.
United States defender Matt Miazga made his first appearance for Nantes on loan from Premier League team Chelsea.
The 23-year-old Miazga won 11 tackles and completed 92 percent of passes in the 2-0 loss to Dijon, the French league's website said.
Miazga left his impression on French football even before joining Nantes. In June, he clashed heads with France striker Olivier Giroud during an international friendly — just one week ahead of France's opening World Cup match.
Giroud needed stitches and started the tournament with his head bandaged.
Marseille can join PSG on six points if it wins at Nimes.
Toulouse hosts Bordeaux, and Saint-Etienne is at Strasbourg.