Barcelona coach Ronald Koeman was fiercely critical of the match officials and VAR following the 3-1 defeat to Real Madrid in el clasico, saying the technology "is only used to make decisions against Barca".
Sergio Ramos was awarded a controversial penalty midway through the second half following a pitchside VAR review when his shirt was tugged by Barca defender Clement Lenglet.
The Madrid captain stepped up to dispatch the spot kick to restore Madrid's lead before Luka Modric sealed the win on 90 minutes to inflict a second consecutive league defeat on the Catalans after last week's 1-0 loss at Getafe.
"I don't understand VAR, I think it is only used to make decisions against Barca," Koeman told a news conference.
"You always get shirt tugs like that in the area and I think Ramos makes a foul on Lenglet first. There's a tug of the shirt, but not enough to make him fall behind as he did ... for me it's not a penalty."
To add to the Dutchman's angst, Barca had two penalty appeals of their own turned down. Lionel Messi went down from a challenge by Raphael Varane in the first half and Barca were denied in the second half when the ball bounced off the arm of Madrid's French defender.
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Neither incident was reviewed by the referee on the pitchside monitor, with Koeman lamenting the lack of VAR decisions to go in Barca's favour this season.
"We have had five matches and [VAR] has only been used to go against Barca. It's never gone our way," Koeman said.
"The decision had a big influence on the final result, because we were playing well up to the penalty. We played well, we created chances and it's difficult to understand how we lost, we didn't deserve to lose how we did."