The 25-year-old might have starred in comparable matches during his time in Belgium and Germany, but admits the game was "nerve-racking with a lot of emotion."
"Luckily we won the game," he says, as City take part in warm-weather training on the grounds of Abu Dhabi's Emirates Palace.
"It's not done yet but obviously a nice feeling to win in the end. Hopefully we can go through against Monaco and see what we can do after that."
Since Sheikh Mansour and the Abu Dhabi United Group began transforming the English club
in 2008, success at this stage of Europe's premier club competition has rarely come easily.
"We've only been in the Champions League for four, five years," De Bruyne reflects.
"Obviously it's something new in the beginning but the team is establishing itself more and more in Europe and last year to reach the semifinal was already good," added the Belgium international, referring to City's loss to Real Madrid last season.
"I think it's getting better and better with the team every year."
At the heart of City's victory, and recent excellent form, has been reuniting De Bruyne with Spaniard David Silva in midfield.
"I think it's going very good; at the beginning of the season we played there and it was going well," De Bruyne says.
"After that we changed it a little bit and the manager wanted to see what was possible in the way the team could play and maybe evolve, but maybe it was not the right time for the team because everything was new for us," he added, referring to coach Pep Guardiola's strategies.
"But I think it's going really well. To play with David and Yaya (Toure) in the last few games, who are so strong with the ball, it definitely helps the team out."
De Bruyne has perhaps been City's standout player over the last two seasons, and was recently compared to Dutch great Johan Cruyff by his former manager at Genk, Hein Vanhaezebrouck.
"It's a big compliment," says the Belgian, typically deflecting the praise. "I try to play the game in the way that I can help the team.
"I know that I'm playing a little more defensive now -- more in the role as team player -- but I think I'm doing really well and so obviously people are looking at statistics.
"In the end I don't care: if we can win more games than last year and I score less, I will be really happy. And maybe if we can win a few titles, that's a bonus!"
De Bruyne is quick to defend the way Guardiola sets up his side, stressing a lot of their issues at the back have derived from individual errors rather than the manager's tactics.
Teams rarely outplay City, says De Bruyne, insisting "it's more the mistakes that we make when we have the ball at the back.
"There's a risk with the way we play. It's not like they created the chances -- we made mistakes, so we got goals against us.
"A lot of people are saying that we're weak defensively but you have to analyze the way we are playing.
"We don't get a lot of chances against us but obviously it's more dangerous when we do because we play so offensively."
'More to come'
For Leroy Sane, man of the match on Tuesday, the performance was just reward for what has been a challenging first season in England.
"It was definitely one of the best matches in my career, and in my time at Manchester City," the $53 million summer arrival from German club Schalke said. "Maybe more will come.
"Of course Monaco is a very strong team. We will look at the different strategies and see what works best to have the same outcome as the first game."
The German believes Guardiola has already improved his game but admits it took time to get used to his methods.
"I had to go step-by-step to adapt to Guardiola's system but I think especially in terms of position and receiving the ball he was very helpful, and I hope to learn from him and the team," Sane said.
"The training is very intense but he gives us a little bit of space because we have a lot of training and a lot of games.
"In the meetings we have to be very focused because he talks a lot about strategy and tactics. This is, of course, mentally challenging."
Amid the euphoria of Tuesday's win, there nonetheless remains a big question mark over City's defending. In the absence of club captain Vincent Kompany, the central defensive pairing of John Stones and Nicolas Otamendi has come under particular scrutiny.
Stones, another big-money signing
, suggests the criticism is often unwarranted, though admits his culpability for Monaco's third goal, when he was outfoxed by Radamel Falcao.
"Just the one action when Falcao got past me," Stones said. "The one vs. one I could have done a lot better ... I think apart from that we were quite solid and defended quite well.
"I try hard in training to work on it. I think there was an element of luck involved but that's what happens, it works harshly against me.
"I'll look at it over and over and see how we can improve on it."
Like Sane, the former Everton defender has endured a tough first season at his new club, but says he's used to being constantly judged.
"It's always going to be harsh, but you've got to take it in your stride and worry about yourself," the 22-year-old says.
"I know when I've had a good or a bad game. I'll always be honest with myself first, hold my hands up and say I made these mistakes.
"That's how I think I'll improve as a player, I've got the right people around me and feel like I'm going in the right direction."
As well as going strong in Europe, City is second in the English Premier League table, eight points behind Chelsea and perhaps the team most likely to catch the runaway leader.
"I think we just got to think about ourselves," Stones says. "If you start thinking about other teams -- about Chelsea, and who they are playing -- you can get sidetracked and not focus on what's important.
"I think our form in the league has picked up and we've got to focus on that and take each game as it comes.
"We're in three competitions; that's something we should be proud of at this stage."
Next up for De Bruyne, Sane and Stones is a trip to second-tier Huddersfield in an FA Cup fifth-round replay on March 1. The winner will face Middlesbrough in the quarterfinals.
After winter trials, the famous win against Monaco may well end up being the turning point of City's season.