After a fairly inauspicious first three matchdays in the Champions League's round of 16, the video assistant referee (VAR) took centre stage on Wednesday, as Atletico Madrid vs. Juventus and Schalke 04 vs. Manchester City saw no fewer than five match-changing decisions as the subject of full reviews.
Not everyone will agree and it is going to take time for everyone to get used to this system, but on the balance of probabilities, VAR got each and every decision correct.
Let's take a look at each incident.
1. Sergio Aguero goal
Schalke's Salif Sane was dispossessed by David Silva, who squared for Sergio Aguero to score. The VAR checked for a foul by Aymeric Laporte on Mark Uth at the start of the move, before allowing the goal.
Verdict: Not for the only time in this match, as we'll see, the process took too long just to check one incident; almost 90 seconds passed before referee Carlos del Cerro Grande confirmed the goal. With nothing to overturn, it was a painful wait for a simple check.
2. VAR overturns Atletico penalty
Referee Felix Zwayer pointed to the spot when Diego Costa had his heels clipped by Juventus defender Mattia De Sciglio on the angle of the box, but replays suggested the contact was outside the area before Costa fell into it and the decision was changed to a free kick.
Verdict: Excellent, quick use of VAR; it took only one minute for the control room to inform the referee the infringement was outside the box and for play to restart with a free kick.
3. Schalke's first penalty
Daniel Caligiuri's shot hit the arm of Nicolas Otamendi; the City player did appear to pull his limb away, but the movement was not instant and his arm was some distance from his body. Key to this decision was the distance the ball travelled before reaching Otamendi.
However, it took almost three minutes for the VAR review to be completed. Protocol should have seen Del Cerro Grande review the incident before making a decision himself, but UEFA revealed at half-time that the pitchside monitor was faulty and the VAR in the control had to make the call.
Verdict: Penalty award correct, but faulty technology does the general perception of VAR no good. That said, the delay was the fault of tools, not ideology.
4. Schalke's second penalty
Del Cerro Grande awarded the penalty for Fernandinho's tug on Sane. While it was perhaps soft, it was not considered a clear and obvious error, although it's not like the VAR could have instructed the referee to take a second look with the TV not working.
Verdict: Fernandinho definitely made contact with Sane, but this was one of those occasions where VAR would probably not have overturned whatever decision was given on the pitch. it's a shame the ref could not check for himself.
5. Alvaro Morata goal disallowed, 70 minutes
Alvaro Morata rose to head home Felipe Luis' cross, but his joy was shortlived. Giorgio Chiellini, who was in front of Morata and preparing to challenge for the ball, had gone down in dramatic fashion and immediately jumped up to protest for a foul.
At first it seemed there was no real evidence of a clear and obvious error, with no footage of the alleged push. But when referee Zwayer reviewed the incident himself at pitchside, he was shown a new camera angle from the opposite goal and disallowed the header.
Verdict: Initially it looked like there was very little in Morata's challenge on Chiellini, but the final angle was damning. It felt like longer, but the sequence took only two minutes. For a decision that required some investigation, that seems acceptable.
One byproduct of this example is that it provides a reminder that VAR officials will have more camera angles than the host broadcaster is likely to show. It seems there will be little hiding place as VAR develops.