“It is a pity. I am very proud for my players. They followed what we prepared.

“Tonight we were a bit unlucky. I think in the second leg we have to play a game against Barcelona and we know his team is very strong and fantastic.

“Qualification is open, it will be very difficult but our performance gives confidence to try and do something incredible.” Our plan was really god. The effort of the players was great, we are talking about 1-1 and maybe we deserved more.” Barcelona will be big favourites to progress in three weeks’ time, but no Chelsea fan will have forgotten the events of 2012, when they scraped into the final on away goals, despite having John Terry sent off.

Chelsea went into the game on the back of two comprehensive victories in front of their own fans, by scorelines of three and four without reply.

However, given that the opposition were West Bromwich Albion, the Premier League’s bottom club, and Hull City of the Championship in the FA Cup, Barcelona were unlikely to have been too concerned, especially as they arrived in London having lost just once in their previous 38 games.

Conte had previously had to explain away defeats by Bournemouth and Watford, each by a three-goal margin, and the latter reverse had been notable for the implementation of a front three featuring Willian and ex-Barca boy Pedro either side of Eden Hazard.

That certainly hadn’t worked, yet Conte decided to try it again on this night of all nights, with Olivier Giroud and ex-Real Madrid man Alvaro Morata watching from the bench.

An early misplaced pass by Pedro caused panic in the Chelsea ranks, but only briefly and the first shot in anger was launched by Hazard, just clearing the crossbar. Antonio Rudiger, having picked out Victor Moses perfectly with a crossfield ball, then headed wide from the corner that followed. It was an encouraging start by the hosts.

Hazard took down a similar one from the other side and jinked into the box, but twice Barca men were in the way of his attempts to pick out a blue shirt.

Barcelona’s reply was a move that could have opened the scoring, but Messi’s chip to Paulinho in front of goal was headed wide. The Brazilian was not highly regarded during his spell at Tottenham and would not have changed any minds with such a tame effort.

Chelsea found themselves starved of the ball for long periods, but Willian had clearly decided that once he got it he was going to run with in and Ivan Rakatic was first in the book for impeding him at full pelt. Marcos Alonso beat the wall with the free-kick, but not Marc-Ander ter Stegen.

The keeper had no chance with Chelsea’s next effort, as Willian won the ball in midfield and sent Hazard on a run. The Belgian was able to lay the ball back to his supplier, who cut inside and blasted a drive that smacked back off a post.

Gerard Pique sent a glancing header wide from a corner at the other end, before Willian hit the other post four minutes before the break, courtesy of reckless defending by Sergi Roberto. Hazard again fired just over, as Chelsea ended the half strongly.

Suarez had been quiet, but he forced Thibaut Courtois into a save with a low drive from an angle after Andres Iniesta had fired a long-ranger over.

It was Willian’s night, however, and the Brazilian’s third attempt to beat ter Stegen, just after the hour mark, ended up in the net. Hazard found him in space around the D following a short corner routine and Rudiger had the presence of mind to make sure he got out of the way of the low, curling effort that followed. No woodwork was involved this time.

The Brazilian was soon in the wars, with a clearance rebounding into his face leaving him with a bloody nose. It didn’t stop him from racing directly towards the Barcelona goal, although Pique did.

Messi’s equaliser arrived straight after an unsuccessful penalty appeal by Suarez, who went down under Rudiger’s challenge. Chelsea had only themselves to blame, as Andreas Christensen’s ball across his own box, meant for Cesc Fabregas, only succeeded in allowing Andres Iniesta to set up Messi for a simple finish.

Chelsea: Courtois, Azpilicueta, Christensen, Rudiger, Moses, Fabregas, Kante, Alonso, Willian, Hazard, Pedro.

Subs: Caballero, Drinkwater, Morata, Giroud, Zappacosta, Cahill, Hudson-Odoi.

Barcelona: ter Stegen, Sergi Roberto, Pique, Umtiti, Jordi Alba, Rakitic, Sergio Busquets, Paulinho, Messi, Luis Suarez, Iniesta.

Subs: Cillessen, Denis Suarez, Dembele, Digne, Andre Gomes, Aleix Vidal, Vermaelen.

Referee: Cuneyt Cakir (Turkey)