LONDON -- Antonio Conte lamented "one mistake" from his Chelsea team but backed young defender Andreas Christensen after Barcelona got out of Stamford Bridge with a 1-1 draw in the first leg of a tense Champions League round-of-16 tie.
Having struck the post twice in the first half, Willian gave Chelsea the lead on 62 minutes when he curled a low shot around a mass of bodies, but a wayward Christensen pass allowed Andres Iniesta to set up Lionel Messi for a vital away goal as the visitors rallied.
Ahead of the match Conte had warned Chelsea would need to play "a perfect game" to earn a positive result, and speaking in his postmatch news conference, the Italian insisted his players had come agonisingly close to meeting his target.
"We were very close to playing a perfect game," Conte said. "I think we paid dearly for one mistake. Against this opponent, this type of player like Messi, Iniesta, [Luis] Suarez ... if you make a mistake, you pay.
"It's a pity because I think, tonight, at the end of the game we are disappointed with the final result. But, at the same time, this game must give us a lot of confidence to trust that, in the second leg, qualification is open.
"It won't be easy, we must be realistic because we are talking about Barcelona, and they showed they are a fantastic, strong team.
"But we showed, too, that if we are ready to work very hard together defensively, but at the same time continue to have the right feeling when we win the ball and are with the ball to create the chances to score, we can try to do something incredible at the Nou Camp."
Christensen, Chelsea's least experienced player, made the decisive mistake for Barcelona's equaliser but Conte insisted that he has no regrets about picking the young Dane, who has enjoyed a breakout season at Stamford Bridge with a series of composed performances in the heart of defence.
"Christensen's performance was great, incredible," he added. "We are talking about a player who is only 21 years old. It's great that he's able to play this game with this maturity and personality.
"Christensen for me was one of the best players tonight. I'm very pleased with his performance."
Chelsea spent much of the game on the defensive, with Barcelona enjoying 73 percent of possession, but created the clearer chances of the two teams by picking their moments to push forward with speed and numbers in transition.
Conte indicated that he will employ similar tactics at Camp Nou next month, adding: "I think we have to respect the opponent.
"In this case, when you play against Barcelona you know very well that, if you want to face them box to box, you are crazy. You go to lose the game, not only 1-0 or 2-0, but like it happens in Spain ... 4-0, 5-0, 6-0. You must use intelligence.
"We are trying to build something important with a lot of young players. When you have many young players, you have to pay something in experience. So you must play an intelligent game, and we are not stupid."