The Catalans dominated possession but fell behind after Willian curled home from outside the area, but Andres Iniesta capitalised on a Andreas Christensen error to tee up Messi, who grabbed a vital away goal for Barcelona with 15 minutes to go.

Positives

Messi ended his personal drought against the Blues and in doing so, saved Barcelona from defeat on a difficult night for them against a Chelsea side which was defensively resolute. The Argentine's goal means Barcelona will be favourites to go through in the second leg on March 14.

Negatives

Although Barcelona had a lot of the ball, the truth is Chelsea were the more dangerous side. Willian hit both posts and with a little more luck, the London side might have been more than a goal clear before Christensen's mistake. While recent results have been passable, their performances have lacked spark. Again it looks like matches on the road could prove to be Barcelona's downfall in the Champions League -- last season they lost heavily at Paris Saint-Germain and Juventus.

Manager rating (out of 10)

5 -- Valverde opted to play Paulinho on the right of midfield despite his poor form since Christmas and had to take the Brazilian off. The coach was not able to change his system to free his creative players from Chelsea's shackles, although the Catalans did pull level.

Player ratings (1-10, with 10 the best. Players introduced after 70 minutes get no rating)

GK Marc-Andre ter Stegen, 6 -- Willian thrice left him rooted to the spot, hitting both posts before finally curling one past the German goalkeeper. However the forward's effort was so well placed there was little Ter Stegen could do. Other than that, bar saving a Marcos Alonso free kick, it was a quiet night for the keeper.

DF Sergi Roberto, 6 -- Solid if unspectacular performance from the Catalan, although he did improve in the final stages as Barcelona looked to overload Chelsea. Had to be stopped on one charge forward by an ugly tackle from Antonio Rudiger.

DF Gerard Pique, 6 -- Barcelona's defensive leader has been playing through a knee injury and it was that, rather than any impressive attacking, that made him look a little uncomfortable at times. Pique was solid and Chelsea were restricted to efforts from range.

DF Samuel Umtiti, 6 -- The France international has enjoyed a spectacular season, although was worried by the movement of Eden Hazard and Willian here, playing opponents a level up from the type of forwards he usually faces in La Liga.

DF Jordi Alba, 6 -- Occasionally managed to get in behind Victor Moses, in a long-running battle down that side of the pitch, to cause trouble. Defensively he blocked Willian off early on and was penalised, but improved after that.

MF Sergio Busquets, 6 -- Barcelona had a lot of the ball and that was in part due to Busquets' typically fine passing and wisdom in possession. Although he was slick on the ball, he couldn't find the final pass to unlock Chelsea's defence despite probing around the box.

MF Paulinho, 4 -- The Brazilian suffered in the game, clearly Barcelona's weakest link, and wasted their best chance before Messi's goal when he directed a weak header wide. After an excellent first half of the season it looks like he has run out of steam.

MF Ivan Rakitic, 5 -- Rakitic had a poor first half in which he was booked for a cynical foul on Willian and then also brought down Alonso when he turned neatly to try and escape the Croatian's attention. His second half was better and his work-rate can never be faulted.

MF Andres Iniesta 6 -- Barcelona's captain had limited influence on the game but was alert and ready when the moment came. Chelsea's tightly-packed defensive lines denied him space but when Christensen sent a loose pass his way, Iniesta burst into life. He unselfishly fed Messi, who scored to earn the Catalans a draw.

FW Lionel Messi, 7 -- Whenever the Argentine was on the ball, both Chelsea players and fans were terrified. However in the first half the Blues shut him down well, crowding around him in numbers and making it seem like he was destined to go another game without scoring. Eventually Iniesta found him in space and Messi mercilessly slotted the ball past Thibaut Courtois.

FW Luis Suarez, 6 -- The Uruguayan didn't come particularly close to scoring, with one cross-shot nudged away by Courtois, but his sweat and toil was where the value of his performance lay. Suarez hounded Chelsea's defenders and his persistence wore them down, with Christensen eventually making his crucial mistake.

Substitutes

MF Aleix Vidal, 6 -- Offered Barcelona more width on the right flank after coming on and helped stretch the game to his side's advantage.

MF Andre Gomes, NR -- Replaced Iniesta in stoppage time.