When the Video Assistant Referee (VAR) was introduced a couple of seasons ago, its main aim was to help officials arrive at the correct decisions.

It might have sucked the energy out of the game, but it did help in some cases. In the instances they've gotten their decisions wrong - it has been messy. Like what happened to Carlo Ancelotti's Real Madrid on May 9.

How often do you see Ancelotti agitated? He is the epitome of calmness and sobriety on the touchline but against Manchester City, he was absolutely sure that his team had been robbed.

Why De Bruyne's goal shouldn't have been allowed

Kevin De Bruyne had just scored a thunderbolt to equalise proceedings. Nothing wrong with the Belgian's shot, only that a few seconds earlier, Bernardo Silva had retrieved the ball after it had crossed the line for a throw in, but the officials failed to spot it.

VAR failed to review it and Ancelotti was so furious that he was booked. We can't imagine the scenes if that becomes the goal that eliminates them next week.

As history shows, there have been more scandalous decisions in the Champions League in the past. Goals and decisions that stood that weren't supposed to. Sports Brief takes a look at some of them.

1. Robin Van Persie red card at Camp Nou

Well, this was more of a harsh booking.

This game was characterised by Jack Wilshere's masterclass helping Arsenal carry a 2-1 advantage to the second leg.

Van Persie was through on goal but fluffed his shot wide only to turn around and see the offside flag raised.

2. Luiz Adriano at Shakhtar

The Brazilian striker enjoyed a glittering nine-year spell in Ukraine, but it was marked by a few dubious moments.

The biggest of them all was a group stage match against Nordsjælland in 2012.

Adriano got a hattrick in that game, but his first goal elicited reactions.

To everybody's bewilderment, Adriano chased down the ball, rounded the goalkeeper and scored. The referee allowed it to stand.

Like everyone else, Nordsjælland's goalkeeper had expected the ball to roll back to him so that he can restart play, but Adriano had other ideas.


3. Cristiano Ronaldo vs Bayern Munich

As Thomas Muller will tell you, Ronaldo has always been the antidote to Bayern Munich in the Champions League.

Only that in 2017, Bayern faithful felt aggrieved after he scored two goals from an offside position.

The five time Ballon d'Or winner put the ball past Manuel Neuer in extra time while in an offside position.

Minutes later, the same happened when Marcelo squared the ball to him while he was in front of the ball, which technically, is not allowed.

Both goals were allowed to stand. And no, VAR had not been introduced then, but it doesn't make it less scandalous.

For Ancelotti and his troops, they can only hope that De Bruyne's goal won't be the difference in this tie.

Cause such defeats sting.