Chelsea produced a spirited defensive display to stop Barcelona from scoring in the first leg of their Champions League semi-final in the Camp Nou. The Spanish league leaders enjoyed plenty of possession, but struggled to create many clear-cut chances. Thierry Henry forced Petr Cech to save and Bojan headed over from two yards, before Cech stopped Alex Hleb's effort. Chelsea almost nicked a goal as Didier Drogba was foiled by Victor Valdes, while Michael Ballack headed just over. But Chelsea boss Guus Hiddink will be delighted with his side's defensive fortitude in keeping a clean sheet - a feat not achieved by any visiting side at Barca this season. It means the Blues will fancy their chances of reaching a second successive Champions League final when they meet in the second leg at Stamford Bridge next Wednesday. For long periods Chelsea had to be content with watching Barca knock the ball around as they gave another masterclass in possession. Chelsea played right into their hands, with Cech among the main protagonists as his long, aimless kicks only served to gift the ball straight back to the home side. But for a team that this season has scored four goals in a game six times, five goals five times and six goals four times, the hosts were unable to broker many genuine chances. For all the twinkle-toed approach play of the industrious Andres Iniesta and Henry down the left, they struggled to get close to the Chelsea goal with the regularity their build-up demanded. Twice in the opening stages Cech flapped at crosses from the left but the Blues survived and they fashioned a half-chance of their own when Florent Malouda's cross found Frank Lampard and he curled wide from 25 yards. Barca were seeing far more of the ball, but they grew increasingly frustrated by Chelsea's solid rearguard action and were quickly reduced to shooting from outside the area. Henry twice chanced his arm, once testing Cech with a low drive and then lashing in a fierce shot from 22 yards that the Czech keeper did well to parry behind. It seemed as though Barca were trying to wear Chelsea down, but they were very close to going in at half-time a goal down. Rafael Marquez's backpass was woefully short and Drogba fastened on to the loose ball only to see his shot well saved by Valdes, the keeper getting up quickly to deny the Ivorian from the rebound. Chelsea's spirits were lifted by their sudden involvement in the match and right at the start of the second half they nearly took the lead again, Ballack flashing a header wide from Drogba's free-kick. The Barca fans were growing increasingly restless at their team's lack of openings and a serious-looking injury to Marquez and a booking for his replacement Puyol that rules him out of the second leg did little to pacify them. But Pep Guardiola's side continued to probe away in their usual manner and half-chances came and went as the off-key Lionel Messi volleyed over before Daniel Alves, in typically fiery mood throughout, stung the palms of Cech from out on the right. Alves went even closer when his 30-yard free-kick brushed the top of Cech's net before Samuel Eto'o, on the day he was linked with a move to Manchester City, raced through only to shoot at Cech's outstretched left leg. Barcelona's best chances came deep into injury time as Bojan, on for Henry, remarkably headed an Alves cross over from point-blank range, before fellow substitute Alex Hleb was foiled by a fine Cech save. Chelsea may not have got the away goal Hiddink craved before the game, but their Dutch manager will surely be delighted by the outcome. Barcelona: Valdes, Dani Alves, Marquez (Puyol 52), Pique, Abidal, Xavi, Toure Yaya, Iniesta, Messi, Eto'o (Bojan 82), Henry (Hleb 87). Subs Not Used: Jorquera, Gudjohnsen, Keita, Sylvinho. Booked: Toure Yaya, Puyol. Chelsea: Cech, Ivanovic, Alex, Terry, Bosingwa, Mikel, Ballack (Anelka 90), Essien, Lampard (Belletti 71), Malouda, Drogba. Subs Not Used: Hilario, Di Santo, Kalou, Mancienne, Stoch. Booked: Alex, Ballack. Att: 95,000. Ref: Wolfgang Stark (Germany). Source: BBC