Video assistance is being trialled at this competition and a sly elbow was spotted and the ref on the pitch alerted, seeing Argentina reduced to 10 men when the score was already 2-0.
Despite being without some big names including AS Monaco's Kylian Mbappé, France are considered firm contenders on the strength of their victory at last year's UEFA European Under-19 Championship.
Guinea head coach Mandjou Diallo said they feel comfortable staying in South Korea, and facing the host nation in their first match isn't much of a concern.
Argentina coach Claudio Ubeda is looking forward to the challenge.
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England brings three players from Premier League champion Chelsea and five from Everton, but they are not considered a front-runner for the title.
Argentina, one of the tournament favorites, was on top for lengthy periods but was unable to match the clinical finishing of the English.
"I think one of the most important impacts of VAR will be not seeing any more clear mistakes", the 2006 and 2010 FIFA World Cup™ referee continued.
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France won the European Under-19 title a year ago and is expected to ease into the last 16 from a group containing Honduras, New Zealand, and Vietnam.
Jean-Kevin Augustin was the top scorer in that title win with six goals and the Paris St-Germain striker should lead the line in South Korea.
Federation Internationale de Football Association has already used video technology at the Club World Cup in Japan last November and at press conference in Seoul, Massimo Busacca made it clear he doesn't want the system to be relied upon in too many facets of the game.
If a match is all square after 90 minutes, both sides will get to use a fourth substitution and, if two hours of football can not separate them, penalties will be taken in a new order.
With the tournament taking place in Asia, continental hopes rest on the shoulders of Japan and host South Korea.
Takefusa Kubo, only aged 15, spent four years playing for Barcelona's youth team before signing for FC Tokyo in 2016. Diallo said his side doesn't have enough information on South Korea, even though the young Taeguk Warriors had friendlies against Uruguay and Senegal before the U-20 World Cup.
"We will give the same amount of preparation for South Korea as we will do for Argentina and Guinea".
His main weapon is the "Korean Messi", Lee Seung-Woo, who plays for Barcelona and is revered for his ball skills.
"We want to go as far as we can, go all the way", said Lee.
"But first we need to take the Argentina game very seriously". The top two of the four-team group automatically qualify.