Life in the big time comes at you quickly. When it strikes, it does with a ferocity that can leave you on your knees gasping for air.
Arsenal have been longing for nights like this for seven years. You need to be careful what you wish for, sometimes.
Thankfully for them, they have a second snap at the whip in a couple of weeks time.
For 90-plus minutes they passed this test with flying colours in the intense cauldron that is the Estadio do Dragao.
Then arrived the harsh reality of European football as Galeno fired home a dramatic winner at the death to break Arsenal’s hearts.
Porto forward Galeno scored a stoppage-time stunner to snatch the victory on Wednesday
The Gunners were made to rue their failure to capitalise on set-pieces as they appeared content to take a goalless draw back to the Emirates before conceding Porto’s shock winner
With all that said, when these two sides come to blows again for the return leg next month you would still expect Arsenal to finish job.
Indeed, it’s gearing up to be some night at the Emirates Stadium following this breathtaking finish.
It’s all part of a learning curve for Mikel Arteta’s team. You can’t win every game.
When you can’t – make sure you don’t lose, particularly in the first-leg of a European knockout tie.
They couldn’t quite keep to their end of the bargain here last night.
But when they board their flight back to England on Thursday morning, they’ll do so knowing the game isn’t over.
This was the kind of night that puts hairs on your chest. One of those nights that require you to be street-wise, shrewd and durable.
And when the pain of this loss simmers, Arteta should take a degree of heart from the way his young side stood up on a nervy night.
But winners win and they’ll need to show more than they did here in Porto to ensure their failure to qualify for a Champions League quarter-final does not extend into a 15th year.
The noise that greeted Porto’s winner was deafening.
For Porto, this game not only offered an opportunity to go deeper into the tournament but a chance to underline their status as European football royalty. They have won this competition twice, after all.
Their billing as underdogs for this tie irked the locals. How many times have Arsenal been European champions?
They certainly proved a point here on Wednesday night.
The start from Arsenal was controlled, though Declan Rice did pick up a yellow card inside two minutes. Little in the way of chances for the Gunners, yet plenty of the ball.
Porto’s plan was clear: rapid counter attacks reliant on the speed of Francisco Conceicao and Galeno on either flank.
Their strategy nearly worked a treat, as they went within inches of taking a 22nd minute lead when Galeno crashed an effort onto the post before firing the rebound wide with the goal gaping.
The home were convinced he’d scored as the ball rebounded off the advertising hoarding to ripple the net. Indeed, the tannoy operator blared out the song that greets all of Porto’s goals here only to hastily hit the stop button when he realised his error. But it was Galeno’s error that truly cost Porto.
Mikel Arteta’s side remain the overwhelming favourites for the tie ahead of the second-leg
Galeno squandered the best chances of the game early on after he hit the bar and instantly misplaced a follow-up effort on the rebound, stunning the stadium with the unfortunate miss
It was a let off for Arsenal, who struggled for fluency during the opening 30 minutes. Their first genuine chance arrived in the 35th minute, Kai Havertz – back in the stadium he scored the tournament winning goal for Chelsea back in 2021 – taking up a menacing position at the back post only to head Bukayo Saka’s corner tamely wide.
In fact, it was Porto carving out the most promising openings, Nico Gonzalez firing narrowly wide from distance before Conceicao forced David Raya into a smart save with a shot from a tight angle.
Credit to the Portuguese side. Their strategy to stifle and hit Arsenal on the break was effective.
Yet there were signs towards the end of the opening 45 minutes that Arteta’s side were gradually getting to grips with what was required.
Like a mathematical equation, Arsenal’s young team were trying to work out how to crack the code.
As brilliant as they can be, you forget this is an altogether new experience for this collective of Arsenal players. They are learning on the job.
Finding the answers won’t always come naturally to them.
Gabriel Martinelli, largely anonymous in the first half, was starting to find more joy down Arsenal’s left while Martin Odegaard’s influence drew with each passing minute.
Leandro Trossard squandered a good opportunity in the 56th minute, firing over the bar inside the area from Rice’s corner.
Porto’s forays forward had become increasingly fleeting. Arsenal, suddenly, the team in the ascendancy.
Brazilian centre-back Gabriel headed one of Arsenal’s many set-pieces over the bar late on
The fixture was the Gunners’ first Champions League knockout clash in over seven years
There was a certain unpalatable guile to Arsenal’s game that you couldn’t help be impressed by.
The ability to win free kicks or concede them in order to prevent counter attacks. Not traits you’d necessarily associate this Arsenal team at it’s free-flowing best.
But you can’t always have it your own way and this was one of those occasions. The home crowd that was fervent during the first half had been suppressed.
That was until the last of four minutes of stoppage time when Galeno blew the roof off with his brilliant winner.