"We paid dearly for one mistake because we were very close to playing the flawless game", said Conte, whose side now faces daunting Premier League matches at both Manchester clubs.
Messi, 30, has played every match for Barca this season apart from the first three rounds of the Copa del Rey, scoring 27 goals in the process.
So, Chelsea played Barcelona last night at Stanford Bridge and although 1-1 isn't a bad score for the Blues, all things considered, they'll still be ruing the fact they threw away their lead with a loose pass.
The Argentine maestro, teed up by Andres Iniesta after some sloppy play by the host, struck a low shot past keeper Thibaut Courtois for his first goal in nine attempts against Chelsea.
When you play against Barcelona, we know that if we want to play against them box to box then we are insane. "I think it's going to be a different game from this one here but I think we can go there and win this game".
Willian's fine strike just after the hour mark had put Chelsea in command after earlier hitting both posts in the first half.
"And not 1-0 but, like happens in Spain, 4-0, 5-0, 6-0".
The draw gives Barcelona the slight-edge, courtesy of that away goal, in the second-leg which is scheduled for 14 March, but Barcelona will have to be on their game as Chelsea showed they are more than capable of upsetting the apple-cart given half the chance. Against teams like Barcelona, and specifically Lionel Messi, you need to be at your best for the entire 90 minutes, that's what makes them so risky.
Former Barcelona midfielder Cesc Fabregas said: "We have to go there to attack and score because 90 minutes defending at the Nou Camp is an eternity, a suicide mission".
"It's a pity, because tonight at the end of the game we are disappointed [for] the final result". "Barcelona were fighting so hard to create a chance, and then one mistake opened us up".
"I think we played a really good game and I must be pleased because my players gave a great effort and they followed the plan we prepared", said the Italian. Competing for a corner is something we've done thousands of times and to see those consequences for a top professional like Ryan is heartbreaking.