Chelsea began life after Andre Villas-Boas with a victory, winning 2-0 away at second tier side Birmingham City in an FA Cup fifth-round replay to book a quarter-final place.
The Blues, who last weekend saw Andre Villas-Boas become the sixth manager to be sacked by Roman Abramovich since the Russian billionaire bought Chelsea in 2003, had to wait until the second half at St Andrew's to take the lead against second-tier Birmingham.
But two goals in six minutes approaching the hour mark from Juan Mata and Raul Meireles gave Roberto di Matteo a winning start to his reign as Chelsea's caretaker boss.
The Londoners, held to a 1-1 draw by Birmingham in the original tie, could then afford to see Mata's penalty saved by goalkeeper Colin Doyle.
"The attitude was right, the commitment was right and it was important that we showed we cared and made the next round of the FA Cup," said Di Matteo, previously Villas-Boas's deputy.
"We have two months left of the season and we are all in the same boat," he added. "We have to help each other and all 25 players in the squad will need to play at their best. This win was for Andre Villas-Boas."
Di Matteo received a warm reception from Chelsea's supporters. The Londoners will be at home to another Championship team in Leicester City in next week's quarter-finals.