Lionel Messi's 90th Champions League goal, a counter-attacking masterpiece complete with cool finish from Neymar's pass, put Barcelona in control as half-time approached.

The whole emphasis of the game changed, however, six minutes before the interval when Sergi Roberto's mistake allowed Raheem Sterling to set up Ilkay Gundogan's simple finish.

City, seeking their first win over Barcelona at the sixth attempt, were irresistible from then on as Kevin de Bruyne's free-kick curved past Marc-Andre ter Stegen in the 51st minute.

Andre Gomes crashed a shot against the bar as Barcelona pressed for an equaliser, but City wrapped up a landmark win against manager Pep Guardiola's former team with 16 minutes left when De Bruyne played in Jesus Navas and, when his cross fell loose from Sergio Aguero, Gundogan was once more on the spot to score.

City will reach the knockout phase of the competition if they win on 23 November at Borussia Monchengladbach, who drew with Celtic on matchday four.

Guardiola's methods may have been questioned after City's 4-0 defeat at the Nou Camp, but this was just the sort of night Manchester City's Abu Dhabi-based owners had in mind when they finally lured him to the Etihad.

City wanted to make the leap from the second tier of Europe's clubs into the elite and nights like this, and performances like this, will increase confidence that he is the man who ensures they can bridge that gap.

This was a win achieved with all the Guardiola hallmarks, in a blaze of attacking football, passing, movement and a willingness to take on the best without forsaking his principles.

It was the most significant win of Guardiola's reign so far - and offered up the rich promise of more to come.

City's big guns blow away Barca

Barcelona may have been missing the defensive power of Gerard Pique and the midfield influence of Andres Iniesta, but nothing should be taken away from the manner in which City exerted control and dominated the Catalans once they had equalised.

Whereas Barcelona's big three of Messi, Neymar and Luis Suarez faded, City's big players came to the fore and terrorised Luis Enrique's side in the second half.

Aguero ran with courage, threat and unlimited energy, Raheem Sterling - one piece of poor control aside - was outstanding and was denied a clear penalty early on, while Belgian De Bruyne was peerless.

He scored City's second, unlocked Barcelona's defence for the third and looked a player of world class, fully deserving his standing ovation when he was replaced near the end.

City will grow in belief after overpowering Barcelona - and proved they have the players who can trouble the very best teams in the Champions League.
How far can City go?

Early days, but Guardiola knows what it takes to win the Champions League after guiding Barcelona to victory in 2009 and 2011, and Manchester City will take huge encouragement from this win.

City will feel that after beating Barcelona in this manner they can be a match for anyone, although questions remain about a defence that is not exactly risk-averse.

The big news for City and Guardiola is that they matched Barcelona for quality in this classic. There can be no bigger tribute than that.
Man of the match - Kevin de Bruyne

What the managers said

Manchester City manager Pep Guardiola: "They had an amazing 30 minutes, we had a lot of problems but our first goal helped us a lot.

"In the second half we created a lot of counter attacks. I am so happy for the guys, it is the first time we have beaten the best team in the world.

"Today is a good step. We play against a great team and we compete. Now they will realise, 'Wow, we won against the best team."

Barcelona manager Luis Enrique: "It was one of the best 40 minutes we have played on a stage like this against top-quality rivals.

"After the error for 1-1 we had a bad time. When you concede in that way it is normal that you go through a bad period.

"We hoped to continue to dominate but couldn't because of errors we made and pressure from the opponent also.

"We did not have as much possession. We were not able to control the game in the same way. First 40 for us and 50 for them and the score reflects that."
The stats you need to know

    Barcelona's defeat by City ended a run of seven successive wins against English sides in Europe
    City scored more goals against Barcelona on Tuesday than in their previous five Champions League games against them
    An English side have scored three or more goals in a group stage game against Barcelona for the first time since Manchester United in 1998-99
    Lionel Messi has scored 16 goals in his past 14 Champions League games against English opposition
    Ilkay Gundogan has been involved in five goals in his past two games for City (four goals and one assist, all competitions)
    Raheem Sterling has six assists in 16 games for Manchester City in all competitions this season, having provided eight in 47 last season

What's next?

Manchester City host Middlesbrough in the Premier League on Saturday and their next European commitment comes on 23 November at Borussia Monchengladbach.

Barcelona travel to Celtic on the same night, after a trip to Sevilla - fourth in La Liga - on Sunday.