COPENHAGEN, Denmark -- It's possible to have good moments against Manchester City. They can even be beaten over 90 minutes as Wolves, Arsenal, and Aston Villa have already proved this season. But beating Pep Guardiola's team over two games -- with one at the Etihad Stadium, where they haven't lost for more than a year -- is something else.

City have only lost one two-legged UEFA Champions League knockout tie in nearly five years, and even that required something of a miracle from Real Madrid when they scored twice in stoppage time at the Bernabeu in 2022. It begs the question: who can stop the reigning champions of Europe from reaching a third Champions League final in four years?

FC Copenhagen had their moments in their round-of-16, first-leg tie at Parken on Tuesday but they were outplayed for much of the game and were beaten, as most had expected, 3-1. The scoreline probably should have been even more comfortable.

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Despite beating Manchester United and drawing with Bayern Munich in the group stage, the Danish champions, playing their first competitive game for two months, could barely lay a glove on their visitors and face a near-impossible task at the Etihad in three weeks. Real Madrid, with Jude Bellingham, and Bayern, with Harry Kane, would fancy their chances of going toe-to-toe if later draws bring games against City, but the current holders are favourites to win the competition again for good reason.

"I know how difficult it is," Guardiola said afterwards. "People believe it is easy but ask United and Bayern. It's a really tough opponent. We made perfect concepts today. My job is to warn the players about the attributes they have.

"We behaved with character, personality and patience. Everyone was at a top level. It's not decisive but it's a good result. Hopefully, we can make the quarterfinals."

FC Copenhagen tried everything to derail City. On a freezing night in Denmark, the home fans poured into the stadium more than an hour before kickoff and made as much noise as they could while Jack Grealish, Phil Foden and John Stones were all on the end of some heavy early challenges.

"We knew [they would be physical," said Guardiola, who saw Grealish and Bernardo Silva limp off with injuries. "We talked about it, they are so aggressive." Still, City were able to get into their rhythm quickly.

Kevin De Bruyne, playing in his first Champions League game since last season's final after five months out with injury, could have scored with a header after just three minutes. He eventually scored after 10 minutes, by which time Nathan Aké had poked a tap-in over the bar.

For the first 30 minutes, City had 80% possession and Copenhagen were only allowed back into the game after a horrible wayward pass from Ederson ended up with Magnus Mattsson, making his debut following a move from NEC, scoring from the edge of the penalty area to briefly make it 1-1. Bernardo put City back in front just before half-time and Foden added a third in stoppage time but the only surprise was that the result wasn't more emphatic after Copenhagen conceded 27 shots and 13 on target. They have goalkeeper Kamil Grabara to thank for making sure the tie isn't over already.

The one hope for Copenhagen is that the return game in Manchester on March 6 is sandwiched between Premier League fixtures against Manchester United and Liverpool and it's possible Guardiola might rotate his squad. The hope for the likes of Real Madrid and Bayern is that City continue to show small spells of vulnerability, having kept just 11 clean sheets in their past 37 games in all competitions, but with players like De Bruyne -- who scored one and made two against Copenhagen -- they will always score. With three goals against Copenhagen, they became the first team in Champions League history to score at least three goals in seven consecutive games.

"We played really good," Guardiola said. "The right tempo we should play. We managed the game. The first game in the last 16 is always so dangerous but the players behaved and performed really good.

"We'll prepare for the [second game] knowing we're not through. It's one game at a time.

"It was really, really good. I'm so proud. It was important. Today was perfect."

City haven't been knocked out of the Champions League in the last 16 since losing to Monaco in 2017 and everything points to that run being extended once Copenhagen pay a visit to the Etihad. Guardiola, though, will have his sights set much higher, and given their record in knockout ties, you wouldn't bet against another final appearance at Wembley in June.

The question facing the rest of Europe is: who can stop them?