Ernesto Valverde believes Barcelona still has a tough second leg encounter, and are yet to qualify for the quarterfinals.
Barcelona hold an away goal advantage against Chelsea, after Messi scored his first goal against the Blues in 9 matches.
Chelsea looked set to snatch the win with a lone goal courtesy of Willian, but a Christensen error condemned the Blues to a draw.
Nevertheless, Valverde does not see the encounter as one that has been decided.
“The equaliser was very important, scoring here,” Valverde told a post-match news conference. “They might be happy with the result and we have to be respectful with their style of play.
“They didn’t make as many passes as us, but they pressed high and made it difficult for us. The away goal isn’t definitive but it is important.
“We make it a very positive thing. It was a clash of styles. We tried to control the game. We had a lot of possession and tried to get close to the goal. They tried to get us on the counter.
“We had a lack of quality in the final third. There was a lot of congestion and they defended well. Willian hit the post a couple of times. We lacked clear-cut chances.
“But we managed to get an error out of them and get the equaliser and it is a good result in the end.”