Borussia Dortmund head coach, Marco Rose, blamed VAR for the Bundesliga side's 3-1 UEFA Champions League defeat to Ajax on Wednesday after a contentious red card for Mats Hummels was upheld by the video assistant.
Replays showed the German centre-back's sliding challenge had not made contact with Ajax's Antony just before the half hour mark and the Brazilian forward had actually landed on the defender's shin.
But VAR upheld English referee Michael Oliver's decision to show the red card, with Hummels seeming stunned as he walked off.
Despite the red card, a Marco Reus penalty after 37 minutes gave Dortmund the lead until Dusan Tadic leveled the score for Ajax in the 72nd minute, before goals from Sebastien Haller and Davy Klaassen gave Ajax the win.
Ajax had thrashed Dortmund 4-0 in the first game in Amsterdam last month, but the German team was much more competitive on Wednesday even without striker Erling Haaland, who watched from the stands with a hip muscle injury.
Ajax are assured of qualifying with four wins from four games in Group C and have a six-point lead over Dortmund and Sporting Lisbon, who are locked together on six points and meet each other in three week's time in Portugal.