Chelsea secured their place in the quarter-finals of the FA Cup with a 2-0 win away to Birmingham on Tuesday as they triumphed in their first match since manager Andre Villas-Boas was sacked.

Two goals in six second-half minutes by Juan Mata and Raul Meireles ensured Roberto di Matteo, who helped Chelsea land five trophies in six years as a player, got his reign as caretaker boss of the west London club off to a winning start.

Chelsea, who had midfielder Frank Lampard and striker Didier Drogba on the substitutes' bench, were sluggish in the first half before booking a last-eight tie at home to another Championship club in Leicester on March 18.

"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.

But the travelling fans at St Andrew's made it clear whom they wanted to take permanent charge when they chanted the name of former manager Jose Mourinho during a fifth round replay caused by a 1-1 draw at Stamford Bridge.

Former Italy midfielder di Matteo kept senior players Lampard and Drogba out of his starting side, with the pair on the bench alongside regular captain John Terry, who has been out since January with a knee injury.

There were five changes in all to the Chelsea side that lost 1-0 at West Brom three days earlier in Portuguese boss Villas-Boas's final game in charge.

The di Matteo era almost got off to a dream start when Mata found himself in space inside the Birmingham penalty area in the second minute.

But instead of squaring the ball to Salomon Kalou for an easy tap-in, the Spaniard went for glory only for keeper Colin Doyle to make the save.

Birmingham lost striker Nikola Zigic for four minutes while the Serb received stitches after an accidental boot to the head from David Luiz.

Yet at times it was difficult to work out which team was from the second-tier as Chelsea struggled to hurt their opponents.

Their first-half display was summed up when Ramires burst into the Birmingham penalty area but, under pressure, the Brazilian fired his shot wide.

Birmingham, who had already claimed one top-flight FA Cup scalp in the shape of Wolves, grew more confident as the tie wore on.

Former Valencia player Zigic, recovered from his head knock, forced Petr Cech into a stunning one-handed save five minutes before the break.

Then, in the dying moments of the first half, Chelsea's Fernando Torres spurned a great chance to fire his side ahead when he screwed his shot horribly wide from 16-yards.

It was left to Torres's fellow Spaniard Mata to make the all-important breakthrough as Chelsea killed off Birmingham with two quick goals.

A 54th minute cross by Ramires caused major problems in the home defence and, after Kalou had an effort blocked, Mata prodded the loose ball over the line.

That may have been a scrappy goal but Meireles's 60th minute effort was good enough to grace an FA Cup final -- let alone a fifth round replay.

The Portuguese gave Doyle no chance with a 25-yard strike after more good work by Ramires.

Chelsea could even afford to miss a 69th minute penalty after Torres was brought down by Guirane N'Daw, Doyle doing well to keep out Mata's effort.

It was anything but a vintage Chelsea display and they will have to play better if they are to overturn a 3-1 first leg deficit when Napoli visit Stamford Bridge in the Champions League next week.

But after a traumatic few days, victory was all that mattered to Chelsea.