The 29-year-old goalkeeper was delighted as his side managed to keep a clean sheet against the Catalan giants, but remains wary ahead of their second-leg trip to Camp Nou.Petr Cech believes Chelsea \"can be proud\" after beating Barcelona 1-0 at in their Champions League semi-final first leg at Stamford Bridge.The goalkeeper accepted that his side rode their luck at times and also admitted that it had been tough for his team-mates to adapt to a game where they had little possession.\"We can be proud of what we have done today,\" Cech told Sky Sports News.\"There was amazing quality in the team, everyone gave 100 per cent. We are not used to playing 90 minutes without the ball. Mentally it is difficult to keep the focus.\"We have been brilliant all over the pitch, the commitment to defend and cover everyone, we had a bit of luck but everyone did as they were asked.\"Cech was part of the Chelsea side that got knocked out of the Champions League semi-finals by Barcelona in 2009 and he is determined to make sure history does not repeat itself.\"Let’s see [what will happen] the last time we got a clean sheet at Camp Nou and we got a 1-1 here and we went out. This time they didn’t get an away goal,\" he said.\"It’s never easy to say 1-0 is an advantage against Barcelona. They are an exceptional side. They will always create something.\"With a trip to Arsenal this weekend, as well as the FA Cup final against Liverpool next month, the 29-year-old is remaining focused ahead of the return leg at Camp Nou next Tuesday.Cech continued: \"The games are coming thick and fast and we don’t really have time to think, every game is a big focus. Next we play Arsenal, which is a massive game and then we go back to Barcelona.\"