Chelsea will spend Saturday evening back on top of the league table following a morale-boosting derby demolition of West Ham.
Alex gave the home team the lead in the first half, only for the visitors to equalise before the break but unlike against Manchester City in the last league fixture, it was Carlo Ancelotti's men who kept their nerve to add three more goals.
Didier Drogba weighed in with two to give him 27 for the season and between those came a goal from Florent Malouda who played as well as anyone as Gianfranco Zola's side were sent even deeper into trouble.
In Ancelotti's team selection, Malouda had moved forward from midfield to left of the front three with Kalou making way. Ferreira kept his place at left-back with Zhirkov returning from injury on the bench. Ballack came straight back in after suspension.
The game kicked off with a red ball that is on view in matches across the globe this weekend to promote HIV and AIDS awareness and the first chance came Malouda's way within two minutes. In space but off-balance, he sliced it wide. 
A Malouda corner was headed on by Ballack on five minutes but a stretching Alex couldn't reach it at the far post.
Drogba had no trouble making contact with a volley soon after but his fierce strike deflected wide off a Hammers defender. The newly-crowned African Player of the Year then ran out of space in trying to convert a Ballack pass.
It took 12 minutes for West Ham to mount an attack but when they did they should have scored. Spector bundled the ball past Ferreira, Mido crossed but Ilan failed to test Turnbull as he skied his shot high over the bar.
Mido and Ilan, along with Dyer, were part of a completely changed front three selected by Zola. Carlton Cole had an injury concern and was on the bench.
Chelsea were soon up the end and when our chance came, Alex buried it with his head. The big Brazilian had won the ball in the air initially inside the opposing area, Terry got involved and Malouda crossed well for the finishing touch to be applied from eight yards out. It was Alex's first goal of the season.
That was on 15 minutes and a minute later the ball hit the Hammers' bar, Upson having diverted a cross in that direction. Under heavy Blues pressure, it was eventually cleared.
Lampard was crowded out of an attack when Malouda and Drogba had nearly played him in and it was all going pretty smoothly for Chelsea. That was until 29 minutes when former Blue Scott Parker conjured a goal out of next to nothing.
Taking a long throw that Mikel perhaps should have cut out, the midfielder caught his volley from five yards outside the area with the perfect loop to curve over the top of Turnbull's aborted save and into the Matthew Harding End net.
Just as against Man City in the last league game here, the visitors were back level and again it was unmerited on the play. Would Chelsea now crumble as they did then?
Green in the West Ham goal did well to save a Lampard shot low down by the post and then he had to stand still and field a header as Ferreira threatened to score an unlikely goal. That too was from a Malouda across and the Frenchman was having plenty of success in finding space and send the ball in against Spector on the West Ham right. It needed someone on the end of those crosses though.
The first significant moment of the second half was a booking for Mido for a challenge from behind on Ballack deep in the Chelsea half.
Another Malouda cross threatened to find Ballack before Mido intervened. With Malouda's next ball from the left the Blues restored the lead, this time Drogba heading home from nearly under the bar having sprayed the ball wide in the first place. And who opened the defence up in the first place with a surging run up the pitch and into the area? John Terry.
There were 10 minutes of the second half gone and a minute later it took an extremely good one-handed save from Green to prevent Alex heading his second. The cross for once had come from the right - Ivanovic curling it in. Terry nearly scored with the rebound off Green's save.
Joe Cole was introduced after 65 minutes for Anelka and Zola swapped Carlton Cole for Mido and Stanislas for Dyer a minute later.
It was all Chelsea during this midway period in the half. Mikel drilled just wide with a crisp effort after Drogba was harshly denied a free-kick right on the edge of the area.
On 76 minutes came the goal Malouda's performance richly deserved. A Terry long ball was chested to the scorer by Drogba standing strong and showing immense composure, Malouda stepped inside Gabbidon and passed the ball into the bottom corner.

Drogba could have added a rapid fourth but his stretch didn't quite reach a Cole pass.
Lampard rolled a shot against the post following more Malouda trickery with five minutes to go and Drogba was denied on the follow-up by a last-ditch block.
Malouda's game, during which he had supplied 16 crosses, came to an end to the accompaniment of great applause when Kalou was put on for the closing moments.
There was still time for Drogba to net his second, smashing in from close-range after Green could only parry Lampard's stinging low shot as Chelsea broke with speed.
In stoppage time came a confidence-boosting save by Turnbull from Kovac at his near-post.
Bring on Inter on Tuesday night!
Chelsea (4-3-2-1): Turnbull, Ivanovic (Zhirkov 79), Terry (c), Alex, Ferreira; Ballack, Mikel, Lampard; Anelka (J Cole 65), Malouda; Drogba.
Scorers Alex 15, Drogba 55, 89, Malouda 76.
West Ham (4-3-3): Green; Spector, Gabbidon, Upson (c), Deprela; Kovac, Parker, Behrami; Ilan (Diamanti 83), Mido (Cole 66), Dyer (Stanislas 66).
Scorer Parker 29.
Booked Mido 49.