It has been 14 years since Arsenal made it to the quarter-finals of the Champions League — and this defeat was a reminder why.

This was a classic European knockout tie, as Porto used every trick in the book to make it the game they wanted. It was cagey and scrappy, with the one moment of quality coming when winger Galeno curled home the only goal of the game in added time.

Mikel Arteta has spoken about a lack of experience in his team at this level, and of his starting XI last night only Kai Havertz had played in a Champions League knockout game before.

It showed, and as much as Galeno’s goal was a brilliant strike, Arsenal were at fault for giving the ball away far too cheaply when just seconds remained.

Mikel Arteta

They should still be confident about turning this tie around at Emirates Stadium in two weeks’ time, but must be better than this.

“I am very disappointed the way we gave the game away at the end, not managing that situation well enough,” said Arteta. “You get punished in the Champions League. If you cannot win it, you don’t lose it.”

Arsenal have shown themselves to be quick learners under Arteta, and that must continue to ensure they end a run of seven straight exits at this stage of the Champions League.

There are no easy games at this level, and Porto showed they are tricky opponents.

Led by their evergreen captain Pepe, who will turn 41 on Monday, the hosts managed the game well and turned it into a stop-start affair.

They quickly wised up to referee Serdar Gozubuyuk’s willingness to blow his whistle, as shown by his decision to book Declan Rice just over a minute in, and used it to their advantage.

In the end, there were 36 fouls, the most in a Champions League game this season. The ball was also in play for just over 50 minutes, which was the least of all the last-16 first legs during the past fortnight.

Porto constantly broke up the game and stifled Arsenal’s creativity. After scoring 21 goals in five games, the Gunners did not even manage a shot on target here.

Credit must go to Porto for that. They were well organised and swamped the middle of the pitch by playing two defensive midfielders.

The end result was Arsenal captain Martin Odegaard dropping deeper and deeper to get on the ball, with the Gunners’ forward line increasingly isolated.

Porto, in fairness, did not create much, either — although Galeno missed a glorious chance in the first half. After hitting the post, the winger had the goal gaping from just yards out, but he fired the rebound wide. It caught everyone by surprise, even the PA announcer, who blared music assuming the ball was in.

Galeno made amends with his late strike, and the frustration for Arsenal is that they were just moments from what would have been a good result. Now, they must find a way of overturning the deficit at home, and Porto showed last night they are happy to sit deep.

Arsenal will need to play with the aggression and intensity they have in recent weeks, and a raucous Emirates Stadium should help them do that.

So, too, should the state of the game. This match drifted for far too long, instead of Arsenal taking it by the scruff of the neck.

“It’s clear what we have to do,” said Arteta. “Now, it’s more clear than before.

“You want to be in the quarter-finals, you have to beat the opponent, and we’re going prepare that for our supporters to have a real go. We have to create a special atmosphere and we have to really go for it, and get some momentum in the game and manage the game really well, because today was foul after foul.”

When Arsenal last made the quarter-finals, in 2010, they were in the same position. Coincidentally, Porto were the opponents, and the Gunners overturned a one-goal defeat from the first leg by winning 5-0.

This current Arsenal side have shown they are capable of blowing teams away, but they must learn from a night when Porto gave them a lesson in being street smart.

If they do not, then Arteta can forget about his dream of Arsenal ending their long wait to win the Champions League by lifting the trophy at Wembley in June.