Tottenham manager Mauricio Pochettino predicted the meeting with the exciting and young Dutch side would be an "open and exciting game", but it will take something for it to offer more entertainment than this non-stop wave of drama and emotions.
The insane game started with a breathless 21 minutes, which went 1-0, 1-1, 1-2, 2-2, 3-2, before Kevin de Bruyne dished out his third assist to tee up Sergio Aguero to make it 4-2 just before the hour.
In one final heartstopping twist deep into five minutes of stoppage time, City's packed stadium celebrated what they thought was a last-gasp tie-clinching hat-trick goal by Sterling. I am a bit frustrated as I thought we had some chances.
City manager, Pep Guardiola, says the result was heartbreaking for his players and described the VAR decision at the end as "cruel".
City bowed out of Europe's top competition on away goals on Wednesday, despite winning 4-3 at home to Tottenham.
However, Heung-min Son took advantage of two errors from Aymeric Laporte to go ahead 2-1 - meaning Pep Guardiola's men had to score three times to go through.
Porto had briefly reduced the arrears through Eder Militao, but having lost the first leg 2-0 at Anfield, it never seemed in a position to overturn the deficit. He will surely be hoping that his team quickly forget about last night, and focus on their Premier League ambitions. Their angst was reflected on Twitter as the club's official account sent out: "Huge moment as Sterling's late strike is ruled out by VAR!' There were a huge number of replies underneath, one using a Homer Simpson heart attack gif, another opting for SpongeBob SquarePants". Sport always gives you the possibility to beat teams that no one thinks we are capable of beating.
City still hold their Premier League destiny in their own hands, despite now trailing Liverpool by two points.
Yet what happened in the first leg was only a taste of what was to come at the Etihad on a night of football madness: a pulsating encounter that will go down as a Champions League classic.
- Pochettino on a VAR decision which ruled out what would have been a Raheem Sterling last-gasp victor for City.
"I have never seen something like this, It was tough and insane but we are very proud of our team-mates. And it was clear that we had to be ready for that", he added.