LONDON • With Barcelona having secured a precious away goal, Chelsea's Willian has admitted sitting back at the Nou Camp next month would be tantamount to a "suicide mission" if the English champions are to have any chance of reaching the Champions League quarter-finals.

The Brazilian's fine goal was not enough for victory in a compelling last-16, first leg at Stamford Bridge, after Lionel Messi pounced on a defensive mistake by Chelsea to earn a 1-1 draw on Tuesday night which has left the tie evenly poised.

The Argentinian slotted home his first goal in nine appearances against Chelsea but Willian took heart from a battling Blues display.

"It is still open and we have showed that we can compete and we will need another excellent performance at the Nou Camp to go through," said the live-wire midfielder, who was twice denied by the woodwork in the first half.

"You have to have a lot of personality to play against this team which has 70 per cent of the ball.

"We have to go there to attack and score because 90 minutes defending at the Nou Camp is an eternity, it is a suicide mission.

"We have to play our game."

Chelsea have dumped out Barcelona twice in the knockout stages - most recently in the semi-final in 2012 when they won 1-0 at home before drawing 2-2 in Spain.

A similar result in the return leg would put them through and forward Eden Hazard, who played as a false No. 9 with strikers Alvaro Morata and Olivier Giroud benched, urged his side to be positive for the March 14 return match.

"At least we won't be able to think defensively about the second leg because if we think defensively over there, we would be in a lot of danger," Hazard opined.

"We will go there trying to win because we have to score and we will try to pull off the perfect game as we did today except for the small mistake that we made," added the Belgian.

"It's not over. We can still dream. Qualification is still possible."

But for Andreas Christensen's rash pass across his area in the 75th minute, ruthlessly punished by Messi, Chelsea would have taken a slender lead into the second leg.

Chelsea manager Antonio Conte defended the Dane though.

"Christensen's performance was a great performance. An incredible performance," the Italian told reporters.

"He's only 21. It's great that he's able to play this game with this maturity, this personality. I repeat: Christensen for me, he was one of the best players tonight."

Barca striker Luis Suarez, who was kept quiet for most of the night, said that slip-up could prove crucial. "The goal will give us a huge advantage in the second leg and allow us to have more space in the Nou Camp," the Uruguayan said.

His Croatian team-mate Ivan Rakitic took a dig at Chelsea parking the bus at home.

"At times it seemed like a handball match, because they sat back and waited," said the midfielder. "It is difficult when they have eight players behind the ball."

However, Conte believes it's in his team's hands to do "something incredible" in the second leg.

"We must be realistic. We are talking about Barcelona. They show tonight to be a strong, fantastic team," said Conte. We can try to do something incredible at the Nou Camp."

"You must play with intelligence, especially if you know that (Barca) level is up on us," he added.

REUTERS, AGENCE FRANCE-PRESSE