After Peter Odemwingie had given Albion a 17th-minute lead, the Blues replied with three first-half goals from Didier Drogba, Salomon Kalou and Frank Lampard.
If Chelsea and Ancelotti are to finish the season with little more than a consolation of a Champions League place for next term, then they are going about it the right way.
Ancelotti's side have now lost just one of their last 11 matches in the Premier League, winning eight of those, to cut the gap to Manchester United at the top of the table to eight points.
This was also Chelsea's 14th consecutive top-flight victory against the Baggies, bringing to an end the unbeaten six-match run enjoyed by Roy Hodgson since he took over the managerial helm at the The Hawthorns in February.
Up until the midway point of the first half, and in the wake of Chelsea's Champions League exit at the hands of Manchester United in midweek, a shock appeared genuinely on the cards.
Albion had started the game brightly, and their opener was richly deserved, not least for the exquisite way in which Odemwingie finished a four-man move.
The Baggies, via a series of short passes that involved Youssouf Mulumbu, James Morrison and Jerome Thomas, picked their way up the centre of the pitch from the halfway line.
Thomas' final ball to Odemwingie took a slight ricochet off John Terry, but the pass still found its intended target who sprinted into the area before deftly flicking the ball over the advancing Petr Cech.
It was Odemwingie's 12th Premier League goal of the season, setting a new club record, beating the previous best by Rob Earnshaw in 2005.
However, Albion went into this game with an unenviable record of not having kept a clean sheet for 30 top-flight games, with that soon extended to 31 as Chelsea hit back in the 22nd minute.
A string of passes culminated in Ashley Cole's ball down the left finding Kalou, who delivered a low cross into the six-yard box that goalkeeper Scott Carson failed to push away.
In attempting to atone for Carson's error, Nicky Shorey's attempted clearance at the far post found Drogba who slid the ball home for his 13th goal of the season.
Four minutes later and Chelsea had turned the game on its head, making the game appear simple, albeit again Carson did not help his side's cause.
On this occasion the Albion goalkeeper was low down to a 25-yard Drogba drive, but only succeeded in parrying the ball into the path of Kalou who proceeded to pass his goal into the net with an angled shot from 10 yards.
After being benched at Old Trafford in midweek, Drogba and Kalou certainly made their points, with £50million Fernando Torres the man looking on today until his late arrival just over eight minutes from time.
On the stroke of half-time any hope amongst the home fans of a revival was curtailed as Chelsea put the points to bed.
Again the move appeared effortless, sparked by Drogba dispossessing Albion captain Chris Brunt 10 yards inside his own half before the Ivory Coast striker sprayed a raking ball down the left for Kalou to chase.
With time and space, Kalou had little trouble in latching onto the pass prior to picking out the advancing Lampard who drilled home a low right-footed shot from 15 yards.
More goals should have followed in the second half, initially seven minutes after the restart when Drogba spotted Carson off his line, only for a powerful dipping shot from 35 yards to land on the roof of the net.
Lampard, Kalou and Florent Malouda all had chances to add to the tally, but to no avail, grateful at least all the hard work had been accomplished late in the opening 45 minutes.
Towards the end there was time for Torres to make a cameo and stretch his goalless drought to 871 minutes.
The Spain international did have the ball in the net a minute after his arrival in the 82nd minute, only to be denied by the offside flag.
A mis-kick from 15 yards soon after caused great mirth amongst the home fans, highlighting Torres' woeful time in front of goal at present.