A pulsating encounter at Stamford Bridge sees the Blues head to Spain next week with a slender 1-0 advantage after Didier Drogba's strike late in the first half proved the difference on the night.
It was a remarkable defensive performance by the Blues, carrying out Roberto Di Matteo's instructions to a tee, and while we lived dangerously at times, it was a result our bravery merited in the end.
Alexis Sanchez and Cesc Fabregas had gone close to opening the scoring for the visitors in the first half, while after the break Petr Cech saved well from Carlos Puyol. Right at the death, Pedro was denied by the post, but we held on for a famous win.
Ultimately, it was a result which stands us in good stead for the return leg next week, but our immediate attention now turns to a crucial league match away at Arsenal on Saturday.
Following Sunday's impressive 5-1 drubbing of Tottenham in the FA Cup semi-final, Roberto Di Matteo made only two changes to the side which started the game at Wembley. With David Luiz unavailable after aggravating his hamstring at the weekend, Gary Cahill made his first start in the Champions League since the away leg in Napoli, while there was also a start for Raul Meireles, who came in for Salomon Kalou, with Frank Lampard playing further forward. Drogba, so often the man for the big occasion, started up front for the Blues, with Fernando Torres named among the substitutes.
For Barcelona, Puyol, an injury doubt prior to the game, was passed fit and captained the side in central defence alongside Javier Mascherano, who was preferred to Gerard Pique.
With the visitors enjoying plenty of possession in the opening stages, Chelsea defended deep and looked to utilise the threat of Drogba on the break, and it almost paid dividends on two separate occasions, firstly when he failed to control a Cech kick, and soon after when he opted to take Puyol on instead of holding the ball up and waiting for support.
The Spanish side's ability to open teams up at will was all too apparent, however, when Andres Iniesta played a ball over the top of the Blues' back-four and Alexis Sanchez raced on to it before lifting his strike beyond Cech, only to see it bounce back off the bar.
It was a frenetic opening to the game, and while Drogba was penalised for a tackle on Sergio Busquets, the home crowd quickly became aggrieved as decision after decision went Barcelona's way.
Lionel Messi had been a peripheral figure for the opening 10 minutes, but a trademark run saw the Argentinian tee up Iniesta whose shot was parried by Cech. The rebound fell directly into the path of Cesc Fabragas, but as the former Arsenal man looked destined to break the deadlock, he scuffed his strike and allowed Chelsea to clear.
The ability of Pep Guardiola's side to retain possession before finding a killer pass was beginning to tell, and Cech had to be alert twice in quick succession to prevent Messi from opening the scoring, while Iniesta felt he was pulled down in the penalty area by Cahill, one of the few decisions that went our way early on.
Xavi, so often the man who makes the holders of the trophy tick, was dictating the pace of the game, with one particular pass seeking out Daniel Alves requiring a last-ditch clearance from Ashley Cole.
While we defended desperately, albeit resolutely, at times, as an attacking force we'd been virtually non-existent , with Victor Valdes not having a save to make.
Three minutes before the break, Mikel lost out to Messi on the halfway line, and as the forward broke at speed, he slipped in the advancing Fabregas to his left who cleverly lifted the ball beyond Cech, but as the away fans began to celebrate, Cole, once again, made a wonderful clearance off the line to keep the scores at bay.
Amazingly, and against the run of play, the Blues took the lead in added time of the first half with our first real attempt. Lampard sprayed it out wide to Ramires, and as the Brazilian fizzed a cross to the back post, Drogba was on hand to force his strike beyond the despairing dive of Valdes to give us a priceless advantage,his fifth goal in this season's tournament.
Barcelona, clearly stung by that late first-half sucker punch by Drogba, came out for the second half on the front foot, and Cech was forced into an impressive early save from a curling Adriano effort, while Cahill made a fantastic block from a Messi strike.
Minutes later we rode our luck once more when Sanchez fired wide after exchanging passes with Messi, before Alves blazed high over the bar from an Iniesta cross.
It was Cahill again who brought a roaming Messi run to a halt as the Argentine exposed three Blues defenders, and our January acquisition was enjoying one of his most impressive games in a Blue shirt.
As the game wore on, Messi's influence on proceedings began to increase, and another marauding run required an expertly timed block from John Terry.
Guardiola, sensing an opening, made the first change of the evening, replacing Sanchez with Pedro in a straight swap, while both Ramires and the Barcelona substitute found themselves booked in the space of a couple of minutes for late, albeit fairly innocuous challenges.
Salomon Kalou was introduced to the action with just under 20 minutes, replacing a tired Juan Mata as Di Matteo sensed the necessity for fresh legs in a side who had been overrun for large parts of the game.
Fabregas made way for Thiago with 10 minutes left to play, but it was backs to the walls for the Blues as we came under an inevitable flurry of pressure from the European champions.
Much like the first 45 minutes, there was an impotency about our attacking play, with clear-cut opportunities few and far between, not that the home fans were bothered, as they sung their hearts out, willing their team on.
Cech made a stunning save with five minutes left on the clock, as Puyol flicked on a teasing Messi free-kick which was delivered at pace, making the stop all the more special.
Di Matteo replaced Ramires with Bosingwa in an attempt to shore things up in the closing stages, while Drogba became the second Chelsea player to have his name taken by Felix Brych.
Barcelona looked to have stolen a late equaliser in the dying seconds when Pedro's effort beat Cech, only to bounce back off the foot of the post, while Busquets could only smash the rebound high up into the Shed End.
It was to be the last chance of the game.
Chelsea (4-5-1): Cech; Ivanovic, Cahill, Terry (c), Cole; Mata (Kalou 73), Lampard, Mikel, Meireles, Ramires (Bosingwa 87); Drogba.
Unused substitutes: Turnbull, Essien, Malouda, Torres, Sturridge.
Scorer: Drogba 45+2
Booked: Ramires 68, Drogba 85
Barcelona (4-3-3): Valdes; Alves, Puyol (c), Mascherano, Adriano; Xavi (Cuenca 86), Busquets, Iniesta; Sanchez (Pedro Rodriguez 66), Messi, Fabregas (Thiago 78).
Unused sustitutes: Pinto, Pique, Bartra, Keita.
Booked: Pedro 70, Busquets 75
Referee: Felix Brych (Germany)