(CNN) -- Four-time European kings Barcelona gave Champions League wannabes Manchester City a heavy dose of reality when winning 2-0 at the Etihad on Tuesday.
The victory in the first leg of their Last 16 clash was one of two impressive away performances as French side Paris Saint-Germain thumped Bayer Leverkusen 4-0 in Germany.
Both Barcelona and PSG will now be strongly fancied to make April's quarterfinals.
The buildup to the City-Barca game had been notable for comments made by Chelsea coach Jose Mourinho, formerly in charge of Real Madrid, who said Barcelona had their worst team for "many years."
Nonetheless, they still fielded players of the caliber of Messi, Xavi, Andres Iniesta, Alexis Sanchez and Cesc Fabregas, with Neymar -- who is returning from injury -- on the bench.
Former Arsenal man Fabregas was in no doubt that his team had delivered a reminder of their qualities in Manchester.
"We are top of the league, we had a great result tonight and we are in the final of the Spanish Cup -- there is nothing more you can ask for," said the 26-year-old.
"Maybe we had to prove a point in a way but we did it -- and we did it in style.
"Some people have been talking a bit too much, as usual, and hopefully this might have to shut up for a few days."
After a lacklustre first half, Barca took the lead through a Lionel Messi penalty earned after City's Martin Demichelis had been shown the red card for a professional foul.
Despite playing with ten men for 37 minutes, City had their moments to equalize -- notably through a David Silva volley -- but they were underdone by a sucker punch when Dani Alves doubled the visitors' lead late on.
The result means Manuel Pellegrini's side must score at least twice in the Camp Nou to have any chance of progress.
Barcelona knocked out PSG in the quarterfinals last season but the French side have been in ominous form in recent weeks and turned the screw on hosts Leverkusen from the third minute.
"Tonight, we re-found our collective power, as if it was at the beginning of the season," PSG coach Laurent Blanc told French TV station Canal Plus.
"You may point out Bayer's weakness but I would rather note the PSG performance tonight. We played as a great team, both individually and collectively.
"The squad is in a very, very good state of mind and I also want to congratulate those who came off the bench.
"I really have many options to make my starting line-up, everyone is motivated and focused."
Despite lying second in the Germany Bundesliga, Leverkusen have been in poor form, having lost five of their last seven games.
They got off to the worst start possible when captain Simon Rolfes ceded possession to Blaise Matuidi who slotted home moments later after a neat exchange of passes.
With a fair degree of inevitability, Zlatan Ibrahimovic then took center stage.
Three minutes after converting a penalty, the Swede fired home a stunning long-range effort to give his side a 3-0 halftime lead.
His brace takes him to 10 goals in the Champions League, one more than Cristiano Ronaldo whose Real Madrid side don't play Schalke until next week.
Like Manchester City, Leverkusen were also reduced to ten men as defender Emic Spahic, who had conceded the penalty earlier, was sent off in the 59th minute.
Yet PSG only scored once more after that as new signing Yohan Cabaye, who joined the club from Newcastle United last month, capped the scoring two minutes from time.
"We lost heart, we were too nervous," shell-shocked defender Omer Toprak told Sky Sport Deutschland. "They walked all over us. It was a shame for the fans."
On Wednesday, the next two matches of a staggered Last 16 phase take place when Arsenal host defending champions Bayern Munich and Atletico Madrid travel to seven-time winners AC Milan.