Nicolas Otamendi (left) protested his innocence for Schalke's first penalty
Manchester City boss Pep Guardiola said he is "a big fan of VAR" despite his side conceding two penalties and having a man sent off in a Champions League last-16 first-leg win at Schalke.
Nabil Bentaleb scored two first-half penalties but City rallied to win 3-2.
"It's a penalty. The second one is too," said Guardiola. "Offside too. And the red card can be a red card.
"I trust VAR. I have arguments sometimes but not this time. They are both penalties."
The first of the penalties was for handball by Nicolas Otamendi, with the VAR overturning the referee's decision.
The second was given for a Fernandinho foul on Salif Sane - the video referee confirming the decision, although Sane looked marginally offside as the free-kick came in.
Otamendi was sent off in the second half for a second booking, having been shown his first yellow card for conceding the first penalty. Yellow cards are not reviewed by the VAR.
Leroy Sane and Raheem Sterling scored in the final five minutes to give City victory in Germany, after Sergio Aguero opened the scoring early on.
The screen at the side of the pitch did not work for the penalty conceded by Otamendi, with referee Carlos del Cerro Grande having to rely on the video officials to make the decision for him.
Four VAR decisions on Wednesday - but were they correct?
As well as Schalke's two penalties, there were two big calls in Atletico Madrid's 2-0 win over Juventus in the evening's other game.
Did the pundits think the decisions were correct? And do you?
Otamendi's handball...
Daniel Caligiuri hit a shot from the edge of the area which came off Otamendi's arm, which was down by his side. The referee gave a corner initially but, after a lengthy consultation, awarded a penalty.
Ex-City defender Danny Mills on BBC Radio 5 live: "If it was on the goalline what would you say? A penalty and a red card.
"I don't know what is and isn't handball. Otamendi is trying to get his arm out of the way, it's in a natural position, but it stops the ball hitting the target.
"The problem is not VAR, the problem is the law. The rule for handball is the most convoluted, ridiculous law on the planet.
"But without VAR it would never have been given. Was it a clear and obvious error? That would be my only argument - that it was not a clear and obvious error to overturn the decision, and that is what it's supposed to be there for."
Former City midfielder Michael Brown: "There's no way it's deliberate handball. Otamendi gets set, sees he's in trouble, that it's heading towards his arm. He very quickly tries to put it behind his back but the ball is hit that quick at his arm that he can't get it out of the way.
"It was probably the longest VAR in history deciding the right decision. I don't think they knew. Then finally they give the penalty."
Matt in Manchester: "How can you call that handball? The referee is watching that back via VAR in super slo-mo which is the opposite of what VAR is supposed to be used for. It should be shown in real time. An aid to the ref in the time he gets to see it. Ridiculous decision."
Fernandinho foul...
Fernandinho (on the ground) conceded City's second penalty
Caligiuri whipped a free-kick into the box, and Fernandinho put his hands on Sane, who went down. However, Sane appeared to be offside from the cross. The referee gave the penalty - and the VAR backed him up.
Mills: "Fernandinho is touching his waist. That's not a foul. But maybe because of that their legs get tangled.
"It's not deliberate but he prevents Salif Sane getting towards the ball. I can understand why that one was given."
BBC reader Julian: "So an offside player can still win a penalty? Interesting. I didn't know that rule."
Steve, Bicester: "Both definitely pens. Doesn't matter how long VAR took."
Costa penalty incident...
In Atletico's game, Diego Costa was initially awarded a penalty after being pulled back by Mattia de Sciglio and falling into the box. But the referee spoke to the video officials and awarded a free-kick to Atleti as the foul happened well outside the box.
Nobody could think it was a penalty on closer viewing, but some felt Atletico were lucky to get anything.
Spanish football writer Andy West: "Diego Costa needed less than half an hour to get booked, square up to an opponent, angrily demand a yellow card and dive in attempt to win a penalty. Welcome back."
Morata goal disallowed...
Alvaro Morata fouled Giorgio Chiellini before powering home a header
Alvaro Morata was celebrating his first goal for Atletico Madrid with a fine header from Filipe Luis' cross. However, after viewing the incident again, referee Felix Zwayerhe ruled it out for a push on Giorgio Chiellini.
BT Sport pundit Chris Sutton: "It's the referee's call. Whether we like it or not, I think we can understand it."
SteH11: "The decision to disallow Morata's goal was an absolute robbery! Football is a contact sport and a slight brush on someone's back isn't enough to put my little girl on the floor let alone Chiellini. If you give that you'd see hundreds of fouls per match. So glad Atletico won despite it."
Is VAR working well?Referee Carlos del Cerro Grande wanted to look at a screen for the first penalty decision
The video assistant referee system was only brought into this season's Champions League for the knockout stages, so has only been in use for nine days.
The screen not working at Schalke's ground meant a long delay, with the referee guided by the VAR team instead of being able to watch the incident himself.
City boss Guardiola said: "When a new system starts, it is like a manager arriving at a club. Within a few months, people expect you to win every game 6-0.
"VAR has appeared but it needs time and it will improve. The referee's screen was broken but next time it will be better. I support the initiative because we try to be fair at football and the sometimes the referees are not able to realise with their decisions and need help, VAR's intention is to be of help."
Ex-England defender Mills said: "If the technology's broken, tough. You have to go with the on-field decision. That's what it should have been, that's what you've got to stay with.
"If Uefa says it's down to the referee and his call, that's what it should be.
"You're talking about a multi-million-pound industry and they've only got one monitor? Stick it on the jumbotron! It's ridiculous."
West said: "I'm a big advocate of VAR but I don't like the way it's being applied. It's being overused, it should only be there to correct clear and obvious mistakes. At the moment it's being used for way too many marginal decisions.
"The biggest danger with overusing VAR as we currently are is that everyone will get fed up with it and there will be a big enough backlash to drop it altogether which would be a big wasted opportunity to use something that can make the sport better if it's properly applied."
Bill, texting 81111, said: "Is it just me that thinks VAR could work if it worked on an appeals system a bit like cricket? Each team gets a set number of appeals the captain can decide to use per game (very quickly obviously) but only give the ref 30 seconds or something to decide when viewing the replays?"
