(CNN) -- Chelsea are through to the fourth round of the FA Cup, but they had to fight back from conceding an early goal before seeing off League One Southend United 4-1 on a foggy evening.
Salomon Kalou (left) scored one of the goal as Chelsea eventually reached the FA Cup fourth round.
The London side went into their third round replay on the back of a dismal 3-0 defeat at Manchester United on Sunday, a result that fuelled speculation about the future of manager Luiz Felipe Scolari.
Scolari reacted to that result by dropping under-performing striker Didier Drogba and midfielder Deco from Chelsea's 18-man squad -- with Drogba reportedly the subject of an angry exchange of views with the Brazilian.
Stung by criticism of their Old Trafford display, which came soon after the 1-1 home draw against Wednesday's opponents in the original match, Chelsea began firmly on the front foot with plenty of possession -- but within 16 minutes they had fallen behind.
Chelsea have shown a weakness at set-pieces in recent weeks -- and that manifested itself once again when a Junior Stanislas corner from the right was headed home by an umarked Adam Barrett at the back post.
The visitors fought back and Frank Lampard had a great chance to level matters eight minutes later, but his shot from close-range was fired straight at goalkeeper Steve Mildenhall.
At the other end, an Alex Revell header nearly doubled Southend's lead, but Peter Cech saved well, and on the stroke of half-time Chelsea did make their possession count when Michael Ballack expertly found the top corner from the edge of the box, after Mildenhall and defender Peter Clarke had failed to deal with a cross from the right.
Chelsea began the second-half as they ended the first. England full-back Ashley Cole's long-range effort was well saved by Mildenhall, while Southend still showed their attacking intent with Jean-Francois Christophe headed over the crossbar.
However, on the hour mark, Chelsea took the lead that their possession deserved. A superb cross-field pass from Joe Cole, who was later to limp off with what looked like a serious knee injury, found Salomon Kalou -- and the Ivory Coast striker turned his man on the right-wing before firing an angled shot into the corner of the net.
By now, Chelsea were well on top, and they made the game safe in the 77th minute when a fine move resulted in Nicolas Anelka stroking home Kalou's pass. Frank Lampard's injury time goal completed the scoring and gave the scoreline a slightly unfair look on Southend.
The result means Chelsea now entertain Championship side Ipswich for a place in the last 16 of a competition they won in 2007.
Elsewhere, Daniel Cousin struck 10 minutes from time to put Hull through to the fourth round with a 1-0 win at Newcastle.
However, the main talking point of the came in the 22nd minute when managers Phil Brown and Joe Kinnear were sent to the stands after they squared up to each other on the sidelines following Fabricio Coloccini's tackle on Cousin.
Nicky Butt hit the bar before the break for the home side, while Michael Owen was denied by an excellent save from Matt Duke soon afterwards.
Hull had rarely threatened but booked a fourth-round tie Millwall with 10 minutes left when Cousin tapped into the empty Newcastle net, after Shay Given had blocked Richard Garcia's shot.