Home striker Diego Milito netted on three minutes when he easily turned John Terry and fired in at the near post from six metres, prompting little reaction from Inter's former Chelsea coach Jose Mourinho who had promised not to celebrate.
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"It was a high-level Champions League game," Mourinho told ITV Sport. "I said to my players, 'they are not better than us, they are different to us'.
"Chelsea and Inter can both play better. This is the Champions League, it is difficult to fully express yourself because of the pressure."
Thiago Motta threaded the ball forward and Samuel Eto'o miscontrolled it before strike partner Milito confirmed his excellent form this season by cutting in from the left and beating Cech at the near post.
Chelsea's heads failed to drop despite the vast roar from the Inter crowd and they were soon troubling keeper Julio Cesar, playing despite being shaken in a car crash early this week.
"I think on the balance of play, possession, the shots we had, we were the stronger team," said Chelsea midfielder Frank Lampard.
"We knew they like to soak up pressure and they got the early goal which made it easier for them but we've got an away goal and with a performance like that in London we've got a great chance."
