The Argentinian superstar had not scored in his previous eight meetings against Chelsea, but he put that anomaly right with 15 minutes left to secure a 1-1 draw at Stamford Bridge.
Willian rattled Ter Stegen's other upright before the break as Chelsea broke from their shackles, although an absorbing first period, in which Barcelona's best chance was a wayward Paulinho header from a Messi cross, ended goalless.
Chelsea were on top in the first half, but needed to wait until just after the hour mark to take the lead through Willian. "We can go there and do a great job again against Manchester United".
"Something has seeped into the players because when you reel off the names of the teams that have beaten Chelsea, with no disrespect, Chelsea should have beaten them".
The deep-lying Spanish midfielder was at his brilliant best over the course of the 90 minutes this evening, showcasing both his class and grit in dictating the pace of the game and breaking up muerous unsafe Chelsea attacks.
Lionel Messi last night broke his 730-minute goal drought with a strike that drove a dagger into the heart of Chelsea's Champions League ambitions. It's a good result and I think we deserved the 1-1. "Barcelona were fighting so hard to create a chance, and then one mistake opened us up".
"I was a bit unlucky (hitting the post twice)".
Ernesto Valverde's troops enjoyed more possession in the first 10 minutes of the second stanza but were unable to make that dominance count early on.
Chelsea and Barcelona drew the first leg with the scoreline of 1-1.
"We have confidence", the former Shakhtar Donetsk man said.
This will certainly be a tough test for Chelsea as they aim to beat a Barcelona team who are unbeaten in La Liga this season.
"It is a pity". I repeat: Christensen for me, he was one of the best players tonight. "They will be forced to score and we will have more space". Our plan was really good.
"After the FA Cup game, it was a bit hard to sleep well, because when you have to play this type of game, you have to prepare everything: the big things, and the details", said Conte, who has been under mounting pressure this season.