BAD habits of old came back to haunt Albion as their club-record seven-game unbeaten run in the Barclays Premier League came to an abrupt end against a rampant Chelsea.
It looked like business as usual under new head coach Roy Hodgson when Peter Odemwingie opened the scoring in the 17th minute with his 12th of the season.
But the striker's joy at becoming Albion's highest scorer in a Premier League season was short-lived as the defensive frailties which blighted the hosts' campaign before Hodgson took over six games ago came back to the fore.
Chelsea turned the match on its head through goals from Didier Drogba and Salomon Kalou in the 22nd and 26th minutes respectively.
And Albion's hopes of a comeback were all-but quashed when Frank Lampard stroked home a third in the final minute of the first half - the Blues' ninth goal against the Baggies this term.
The win stretched Chelsea's undefeated league run to seven games and kept up their record of never dropping a Premier League point against the Baggies.
Tenth entertained third at The Hawthorns as Albion searched for the few more points they need to secure Premier League survival, while Chelsea looked to close the 11-point gap on leaders Manchester United and cement Champions League qualification.
Hodgson made his first change in three matches, with James Morrison coming in for the benched Simon Cox.
Chelsea, who left Fernando Torres on the bench, were bidding to bounce back from Tuesday's European exit at Old Trafford and fielded a team packed with stars.
The visitors started confidently and after Youssouf Mulumbu conceded possession, Florent Malouda recorded an early effort on goal, dragging a 20-yard drive wide of the right-hand post.
Backed by a vociferous home support, Albion threatened themselves in the fifth minute when John Obi Mikel and David Luiz produced vital blocks in quick succession to deny Odemwingie and Morrison respectively.
A slick passing move involving Chris Brunt and Morrison scythed open the Blues' defence two minutes later and the approach work just lacked a fitting finish, with Mulumbu side-footing over from 15 yards.
An over-hit Paul Scharner pass enabled Chelsea to break on 13 but Kalou fired well wide after advancing just inside the Baggies' box.
But it was Albion who drew first blood thanks to a terrific 17th-minute move.
Mulumbu drove forward and, after a neat touch by Morrison, Jerome Thomas played Odemwingie through and the Nigerian striker beat the on-rushing Petr Cech all ends up with a delightful dink.
However, Chelsea were level five minutes later - and Albion only had themselves to blame.
Malouda broke down the left and after his low cross evaded Scott Carson's outstretched arm, Nicky Shorey inadvertently diverted the ball back across goal and Drogba made no mistake from 12 yards.
Further Albion defensive frailties saw the Blues turn the game on its head by surging 2-1 ahead on 26.
Drogba was allowed to advance towards the Albion penalty area before firing goalwards from 25 yards, which Carson could only parry into no-man's land.
Kalou was first to the rebound, smashing first-time into the bottom far corner from 12 yards.
Chelsea were now playing like champions and attacking at will.
In the 32nd minute, it took a combination of Abdoulaye Meite and Steven Reid risking life and limb to block Luiz's far-post effort to keep the score at 2-1, after Drogba's free-kick had broken kindly for the centre-half.
Two minutes later, Carson had to pull off a stunning reflex save to keep out Lampard's ferocious 30-yard free-kick which the Baggies No.1 must have seen at the last minute.
Chelsea's quick-fire two-goal blast had well and truly sucked the wind out of Albion's sails and they struggled to get out of their own half.
And it appeared to be game over in the 45th minute when the visitors gave themselves a two-goal cushion.
After Odemwingie had lost the ball just inside the Chelsea half, Drogba sent Malouda clear down the left and the French ace squared to Lampard, who fired past Carson from 15 yards.
Albion did threaten one more time before the interval, when Drogba was in the right place to nod away Jonas Olsson's goalbound header from Brunt's deep corner.
The Baggies regrouped during the interval but it was Chelsea who threatened first after the restart, with Drogba seeing an audacious long-range effort loop onto the roof of Carson's net.
Back came Albion and Thomas cut inside from the left before seeing his 18-yard drive deflected wide by Branislav Ivanovic for a corner.
But Chelsea still looked full of goals and Kalou was only a whisker away from connecting with Drogba's centre at the back post.
Albion continued to look uncertain at the back and it took a smart stop by Carson on the hour-mark to deny Malouda's 20-yard shot.
And the Baggies had a real let-off moments later when the wrong-footed Carson could only watch Kalou's shot loop off Reid and hit the bar. Shorey did well to shrug off Lampard and clear the rebound.
Albion enjoyed some respite when Shorey got forward down the left and crossed to the back stick to Scharner, who headed wide.
Then, on 70, Brunt fizzed a left-footed drive just wide of the left-hand post.
To their credit, Albion kept plugging away but Odemwingie could only scoop a presentable chance over from Mulumbu's pass.
Brunt and Mulumbu both tried their luck from distance in the closing stages but failed to trouble Cech.
Brunt wasted a great chance on 83 when he planted a free header from sub Carlos Vela's centre straight at Cech from eight yards.
Time ran out for Albion in their quest to find a way back into the game but their efforts were not lost on the home fans, who applauded the players off at full-time.
ALBION (4-2-3-1): Carson; Reid, Meite, Olsson, Shorey; Mulumbu, Scharner (Jara 73); Brunt, Morrison (Vela 73), Thomas (Tchoyi 82); Odemwingie. Subs not used: Myhill (gk), Cox, Fortuné, Tamas.
CHELSEA (4-3-3): Cech; Ivanovic (Bosingwa 63), Luiz, Terry, Cole; Lampard (Benayoun 77), Mikel, Essien; Kalou, Drogba (Torres 82), Malouda. Subs not used: Turnbull (gk), Zhirkov, Ferreira, Anelka.
GOALS: CHELSEA - Odemwingie (17). CHELSEA - Drogba - (22), Kalou (26), Lampard (45).
BOOKINGS: ALBION - Meite (foul 34).
REFEREE: L Probert (South Gloucestershire).
ALBION STARMAN: Jonas Olsson.
PIC: MASTER MARKSMAN...Odemwingie chips Cech to make it 1-0