Chelsea reached the FA Cup quarterfinals on Tuesday, winning a replay 2-0 at Birmingham in its first match since firing coach Andre Villas-Boas.
Juan Mata and Raul Meireles scored second-half goals to take the Premier League club through to a meeting with another second-tier side, Leicester.
Interim coach Roberto Di Matteo left Frank Lampard, Didier Drogba, Michael Essien and Daniel Sturridge out of his starting lineup and, after a scoreless first half, Mata poked in a 53rd-minute opener after Birmingham failed to clear a cross by Ramires.
Ramires then set up Meireles seven minutes later for a 25-meter (yard) strike into the top corner.
Tottenham hosts third-tier club Stevenage in another replayed fifth-round match on Wednesday.