The Parisians look to finish the job on March 8.
Barcelona will be looking to pull off a miraculous Champions League come back when they host Paris Saint-Germain.
The night's other Champions League match saw another shock, with Borussia Dortmund stunned 1-0 away to Benfica.
I go into the game with a positive mood.
Despite the 4-0 first-leg victory, Emery underlined his respect for Barcelona and opposite number Luis Enrique but backed his players to keep their nerve.
Barcelona then began to dominate possession, and will be left wondering how they didn't increase their lead quicker than they actually did.
Sergi Roberto of Barcelona celebrates after scoring the team's sixth goal to down PSG. Turan has however participated in first team training this week and was rested over the weekend against Celta Vigo.
PSG, meanwhile, will be boosted by the return of midfielders Adrien Rabiot, Angel Di Maria and Thiago Motta following injuries.
Barca will be relying heavily on Messi to help overturn a 4-0 deficit against PSG in the Champions League last 16. PSG defied all the odds and managed to thrash the Catalonian giants by four goals to nil, a scoreline which was thoroughly deserved and reverberated around the football world. Don't allow four damn goals, and try to slow this game down to a crawl, if possible. At the same token, every road goal is worth twice its weight in gold for PSG.
The fact that the Gunners' best player, Alexis Sanchez, is clearly very unsettled following a training ground bust-up which saw him left out of the game against Liverpool only adds to the impression that the London club is anything but a happy camp at the moment, and it's very hard to imagine them making Bayern's life at all uncomfortable on Tuesday night. "I think it will be important to attack and not just think about defending". But the question is can they stop PSG from scoring?
The first leg of this Champions League round of 16 tie took some time to develop. Luckily, the second half opened with some fireworks, because the first half was actually quite uneventful, to say the least.
Benfica's lone goal came from their only shot that was on frame in the entire match.
At the time very few, even in Barcelona, believed that. Where were you in 1963?
And yet they now sit a point clear at the top after Zinedine Zidane's men (who do still have a game in hand) suffered a 2-1 defeat at Valencia and a 3-3 home draw with La Palmas in the past two weeks.
Asked if he could see in Messi's eyes that the club's all-time highest goalscorer had PSG in his sights, Suarez added: 'It's a game that he wants to play but it's one we all want to play. Are you ready for their road record?
"It's an enormous loss which tarnishes the win".
Barcelona have continually voiced their confidence the 29-year-old will renew his contract, and Braida reiterated that stance.
Concern grew when Barca slumped to a 2-1 defeat at home against newly promoted Alaves after the coach made a string of changes. Both teams to score is priced at (1.42).