Last Updated: 14/01/09 10:03pm
That's it! The full-time whistle goes and Chelsea have progressed courtesy of a 4-1 win at Roots Hall. Thanks for tuning in.
The visitors make it four after Lampard spanks the ball home past Mildenhall after a fine run from Kalou.
Be sure to stay tuned to skysports.com after the full-time whistle for all the post-match reaction from both teams.
Not a lot happening at the moment. Chelsea have thoroughly deserved their win on the night, but it's been an exciting contest.
The visitors have just won their 15th corner of the match. Southend on the other hand have won five.
Kalou squares the ball to Anelka who fires a first-time effort past Mildenhall from 12 yards out. That goal should just about kill off the tie now, but Southend have made it a fabulous cup match on the night.
Cole tried to carry on, but he's still in pain and he will now be coming off. It could be bad news for Scolari if he needs anything more than a few weeks on the sidelines.
Southend have made their first change of the match with experienced striker Dougie Freedman replacing Barnard up front.
Anelka fires his first-time right-footed effort over. Cole is jogging on the sidelines and seems set to return to the action.
Chelsea's physios are currently working on Cole. I'll let you know if he's able to continue. Scolari might take him off anyway, just in case.
Joe Cole is down injured after being fouled by Grant. There didn't seem to be anything in the challenge, but Cole seems in a bit of pain.
If Southend can make sure there is just one goal between the teams late on, maybe they can manage what the did at Stamford Bridge and snatch a late equaliser.
Ashley Cole now crosses into the box, but Barrett is on hand to hoof the ball clear of the danger zone.
Lampard's left-footed cross is caught by Mildenhall. Southend are struggling to halt wave after wave of Chelsea attack.
Southend are just having trouble getting hold at the ball at the moment. Chelsea look more likely to get a third than the home side level matters.
Joe Cole has a sight of goal, but tries his luck from the angle and sends his shot over with Lampard well-placed in the middle.
A superb pass from Joe Cole finds Kalou and he gets inside Herd before lashing a right-footed shot past Mildenhall into the far corner of the net. Fine goal by the visitors.
Christophe heads Stanislas' corner over at the near post. Poor marking there by Chelsea. He should have hit the target after failing to get picked up by Chelsea's defence.
Stanislas whips in a corner, but it's too high for Barrett to get a decent header on target. Good response from the home side.
Chelsea win another corner after Alex seems to send a header over from Lampard's in-swinging corner.
Mildenhall needs to be at full stretch to keep out Ashley Cole's well-struck effort from the edge of Southend's penalty area.
Grant whips in the ball, but Barnard cannot keep his header on target. His effort was a long way out and would have been comfortable for Cech had it been on target.
It's all square at one apiece. Do we have any predictions on how this might end? firstname.lastname@example.org
The players are back out at half-time. I'll let you know if either side has made any changes at the interval.
The half-time whistle goes and it's all square at Roots Hall after Ballack cancelled out Barrett's 16th minute opener for the home side.
Mildenhall makes a hash of Bosingwa's cross. The ball fell to Ballack and he superbly strikes a half-volley into the roof of the net. Crucial goal on the stroke of half-time.
Free-kick for Chelsea in a dangerous position. They need a quality delivery here to cause Southend problems.
Cech pulls off a fine save to block Revell's point-blank header. Amazingly it was nearly a second for Southend.
Ashley Cole's low cross is hooked clear by Clarke. The visitors are just having a bit of trouble breaking down Southend at the moment, but there is a long way to go.
Ballack's volley drifts over. The German collected the ball from Mildenhall's punched clearance, but his effort failed to hit the target.
Ballack's snap shot is deflected wide for a corner. From the resulting set-piece Lampard's cross is headed over by captain Terry.
A fantastic challenge by Clarke robs Lampard of possession in Southend's penalty area. Any mistake with the tackle then would have resulted in a spot-kick.
Southend are being forced deep into their own half. I'm not sure they'll be able to hold on for the next hour like this. The Blues are unlucky to be behind, but they must equalise is they are to survive in the competition.
It's all Chelsea, but Herd is on hand to mop up at the back with Joe Cole ready to pull the trigger.
Somehow Southend have survived! Mildenhall did well to save Lampard's shot and from the rebound the home side manage to block Joe Cole's follow-up.
Anelka nods Bosingwa's cross just wide of Mildenhall's near post. Scolari may be disappointed the French striker failed to hit the target with his effort.
Chelsea will wonder how they are behind. They have been in control from the off, but conceded a soft goal from a set-piece. Southend are up for this one.
A right-sided corner is swung in and Shrimpers captain Barrett rises highest to head home into the far corner of the net. If Chelsea would have had a man on the far post he might have kept the header out.
Southend had half a break on there, but Stanislas' cross is blocked with Barnard making strides to become available through the middle of the pitch.
Lampard's speculative shot is barely worth mentioning. He was well placed around 30 yards out, but he did not catch the ball right ensuring it ended up well off target.
Chelsea are enjoying the lion-share of the possession so far, although Southend are keeping their shape well and are not getting frustrated.
Bosingwa has a chance to cross after robbing Herd of possession, but his right wing effort is poor and floats straight out of play.
Shrimpers keeper Mildenhall produces a fine save to keep out Joe Cole's near post shot. Chelsea look as though they mean business early on.
Ballack runs the ball out of play giving Southend a goal kick. His misfortune draws a cheer from the home support.
A raking ball from Alex finds Kalou who breaks into Southend's penalty area. Sadly for them, no one was waiting in the middle to tap home.
Southend's fans are in full voice early on giving their side as much support as possible. Chelsea are just happy playing the ball around at the moment.
It'll be interesting to see how Chelsea respond to their 3-0 thumping at Old Trafford on Sunday. Scolari can ill-afford and early cup exit with the title challenge on the ropes.
Fog is definitely not an issue at Roots Hall with visibility nice and clear. I'd be surprised if the game is eventually called off for fog.
I'm James and I'll be covering this evening's clash. If you have any talking points or predictions for the Roots Hall clash then feel free to drop me a mail at email@example.com. I'll publish the best of the responses.
Southend: Mildenhall, Sankofa, Clarke, Barrett, Herd, Grant, Christophe, Moussa, Stanislas, Barnard, Revell. Subs: Francis, Walker, Freedman, Betsy, Joyce, O'Keefe.
Chelsea: Cech, A Cole, Lampard, J Cole, Mikel, Ballack, Bosingwa, Kalou, Terry, Alex, Anelka. Subs: Cudicini, Ivanovic, Carvalho, Di Santo, Belletti, Mancienne, Stoch.
Didier Drogba - a reported transfer target for Jose Mourinho's Inter Milan - has been dropped as under-pressure boss Luiz Felipe Scolari names Nicolas Anelka and Salomon Kalou in attack. Ricardo Carvalho drops to the bench, with Brazilian Alex coming in to the defence while Deco is also missing from the squad completely in the other change from the team beaten 3-0 at Manchester United.
Adam Barrett captains The Shrimpers, who earned another shot at the Premier League giants courtesy of a last-minute goal from Peter Clarke at Stamford Bridge. Midfielder Alan McCormack, though, misses out on the big night through suspension.