Thibaut Courtois felt video technology had come to the right decision after Ajax had a goal chalked off in Real Madrid's 2-1 Champions League win.
A header from Nicolas Tagliafico was ruled out by VAR, apparently because Dusan Tadic was in an offside position and standing in front of Real goalkeeper Courtois as the ball looped in.
However, Courtois seemed to think the offence had occurred seconds earlier when Tadic had swung his leg in front of him and the Belgian keeper spilt Matthijs de Ligt's initial header.
"I think it was the right decision, when it happened I thought maybe offside," Courtois told BT Sport.
"It was a mistake by me but I went to go and catch it and Tadic made an attempt to shoot, yet didn't touch it, and as he's offside he's offside.
"Because of his intention I made a quick movement and the ball bounced on my arm. It was an unlucky goal for me to concede but when I saw the screen I saw a possible offside.
"I think it was the correct decision and luckily for us there was VAR because otherwise nobody would have seen it."
The controversial decision meant Real went in at half-time on level terms with all three goals coming in the second half.
Karim Benzema and Marco Asensio were on target for Real but the reigning champions, seeking a fourth straight title, were given a major scare by the only team left in the competition who had to come through qualifying.
As well as the disallowed goal, Tadic hit a post and Ajax were full value for their equaliser scored by Hakim Ziyech.
However, substitute Asensio grabbed Real's winner three minutes from the end.
"I like Ajax very much," added Courtois. "They pressed us really high, it was hard to find space and keep the ball and they played really well.
"They had chances, I made some good saves and we were lucky to win the game today.
"We kept control, scored a really nice goal, they made a good 1-1 and we got another for 1-2 and we are really happy with the victory."
Ajax boss Erik Ten Hag was bemused by the VAR decision.
"Why was it disallowed? I heard several reasons, offside, hindering the goalkeeper. But I have not seen it," he told De Telegraaf.
"We dominated, forced many chances, but scored too little.
"Real never allow many possibilities. This was perhaps our best game of this season. "
