Barcelona outclassed 10-man Manchester City in the Champions League round of 16 on Tuesday, with Lionel Messi netting from the penalty spot in a 2-0 first-leg victory.

The Argentina forward scored his 25th goal in 27 games in the 54th minute, but despite its man advantage, Barca couldn't score again until the 90th through Dani Alves.

"Maybe we had to prove a point in a way and I think we did it," Barcelona midfielder Cesc Fabregas said, referring to previous criticism of the team. "And I think we did it in a style and very, very well."

In the end, it was an unsettling introduction to the knockout phase of the competition for City, with Barcelona's poise and panache enabling the four-time European champions to remain in near-complete control against England's emerging force.

City had managed to repel the waves of attacks by the Spanish champions until the start of the second half when Martin Demichelis couldn't keep up with the speedy Messi, dragging down his fellow Argentine and conceding the penalty.

Even after Messi made it 11 goals in 11 games since returning from injury, City managed to unsettle Barcelona goalkeeper Victor Valdes more than had it with a full complement of players.

But City couldn't grab an equalizer against the run of play, and Barcelona ensured it would win in Manchester for the first time when Dani Alves successfully completed a one-two with substitute Neymar to score the team's 113th goal of the season.

"Today was one of those days maybe everyone was saying Barcelona was not the same Barcelona ... some people were talking a bit too much and as usual they will have to shut up for a few days," Fabregas said. "We are top of the league, we had a good result tonight and we are in the final of the cup [in Spain]. There's nothing else you can ask for."

At the Etihad Stadium, City was playing Barcelona for the first time — and it showed.

But rather than acknowledging the strength of the opposition, City manager Manuel Pellegrini just blamed the referee after the match, questioning his partiality and competence.

In reality, Pellegrini's side struggled from the start to disrupt the visitors' flowing passing moves.

Somehow, though, the hosts emerged unscathed from its hesitant start and produced the first meaningful shot of the match after 25 minutes when Alvaro Negredo curled the ball at Valdes after a dithering defence failed to clear.

City goalkeeper Joe Hart had little to do, despite Barca's control, until he pushed Xavi's long-range strike high into the air.

"When it was 11 against 11 I thought we maybe gave a little too much respect to them in the beginning," City captain Vincent Kompany said. "They were there for the taking."

But after a quiet first half for Messi, his key contribution came after the break.

When Demichelis brought him down, the initial contact appeared to have been made just outside the area, but the foul continued into the penalty area. And in front of the small contingent of visiting fans, Messi dispatched the spotkick past Hart.

It was Messi's first away goal against an English club and his 66th in the Champions League, putting him just five from levelling Raul's record.

Aside from Xavi firing over and Dani Alves skewing another effort wide, City looked more likely to find the net at times in the second half despite chasing shadows for most of the time.

Samir Nasri had a shot blocked by Sergio Busquets and, when David Silva brought down Pablo Zabeleta's cross and unleashed a volley but it went straight at Valdes.

Then a lightening move down the right flank was completed by Dani Alves, giving Barca a comfortable lead as it chases a first European title since 2011.

"They are incredibly efficient," Kompany said. "When you play against them you do realize the individual quality of this team is phenomenal and it makes it so difficult to close them down."

Paris Saint-Germain 4, Bayer Leverkusen 0

Zlatan Ibrahimovic scored twice as Paris Saint-Germain all but booked its place in the Champions League quarterfinals with a 4-0 away rout of 10-man Bayer Leverkusen.

Blaise Matuidi got the visitors off to a flying start in the first leg of their round-of-16 tie by scoring in the third minute.

Ibrahimovic made it 2-0 from a penalty in the 39th, after Emir Spahic hauled down Ezequiel Lavezzi, and effectively killed the game three minutes later when he rifled a shot from outside the penalty area inside the top far corner.

Leverkusen had Spahic sent off for a second yellow card in the 59th and Paris substitute Yohan Cabaye completed the rout in the 88th.

"We had a good game," said Ibrahimovic, who took his tally in this season's competition to 10 goals from six games. "We scored early and when you are in the lead it is much easier."

The result looks almost certain to end Leverkusen's hopes of reaching the quarter-finals for the first time since 2002 with a mountain to climb in the second leg in Paris on March 12.

No team has recovered from 4-0 down in a two-legged Champions League tie.

Leverkusen seemed to be feeling the effect of losing five of its last seven games. The home side looked nervous from the start, perhaps mindful of losing 5-0 to Manchester United in its previous game at home in the competition.

"We played with fear and I really don't know why," Leverkusen defender Omer Toprak said.

Leverkusen captain Simon Rolfes lost the ball to Matuidi, who combined with Ibrahimovic and Marco Verratti before tucking the latter's return pass inside the far post.

"We observed them and saw their [previous] game against Schalke. We knew they were suffering and we didn't want to gift them any confidence," said Paris coach Laurent Blanc, whose side was unbeaten in its previous seven away games, with five of those ending in victory.

The visitors exuded confidence as the home side struggled to compete. Ibrahimovic should have made it 2-0 when Leverkusen 'keeper Bernd Leno struggled to deal with an effort from Lavezzi, but he fired the rebound straight at Roberto Hilbert.

The home side gradually improved. Spahic, who had been doing a good job marshalling Ibrahimovic, tried his luck from distance, though failed to trouble Paris goalkeeper Salvatore Sirigu.

The penalty dented his side's hopes, however, and then Matuidi played the ball back for Ibrahimovic's hammer shot.

Leverkusen coach Sami Hyypia reacted at halftime by bringing Rolfes and the disappointing Son Heung-min off for Stefan Reinartz and the 17-year-old Julian Brandt respectively.

Striker Stefan Kiessling's penalty appeals were ignored and Leverkusen supporters were further enraged when Spahic was sent off with his second yellow card for catching Lucas with his arm in a tussle for the ball.

Leverkusen defender Philipp Wollscheid's blushes were spared in the 66th, when his own goal was ruled out after Lavezzi had strayed offside.

Leno produced a great save to deny Paris substitute Javier Pastore from close range with four minutes remaining, but was helpless to stop Cabaye from emulating Ibrahimovic with a similar finish from Lucas' layoff.

"We also want to win the return game," Blanc said. "We were back to the type of football we were playing in the first half of the season. The players did well. I have to compliment them."