Ancelotti becomes an intense, nervous figure on match-days, a contrast to the equable, homourous soul the rest of the week. The Italian had not felt under pressure following Chelsea's stumbles, the defeats at Wigan Athletic and Aston Villa, primarily because he is aware of the quality of his squad and the support he enjoys in Roman Abramovich's inner circle.
Xabi Alonso targets Chelsea record to underline Liverpools title credentialsStill, Ancelotti also knows that the Russian oligarch craves glory in the Champions League so this untroubled victory, strengthening their control of Group D, was welcome indeed. As well as the realisation that Didier Drogba now returns from his ban, the sight of Kalou shouldering some of the goalscoring burden was encouraging for Ancelotti.
Similarly uplifting was the stirring image of Lampard back to his creative best in midfield, patently enjoying a freer, deeper role, allowing him space to run into. With Michael Essien anchoring well, Lampard kept pushing on, even scoring a fine goal after 69 minutes, a low shot that ended a 10-game drought.
For all the talk of transfer bans, and Chelsea stepped up their fight against the Fifa embargo on Wednesday, they showed they have strength in depth. Ancelotti had demoted Ricardo Carvalho to the bench for Chelsea's defensive glitches at dealing with set-pieces in recent weeks but Branislav Ivanovic did well enough alongside John Terry.
Yuri Zhirkov, an accomplished Russian international, came off the bench. So did Danny Sturridge and Florent Malouda. Joe Cole's return from lengthy injury gives Ancelotti another option, particularly at the forward point of the diamond.
Wednesday night's formation was 4-1-2-2-1, more Christmas tree, and certainly blessed with rich pickings for Kalou.
Before Kalou discovered the way to goal, the game had been disappointing, starting in slightly desultory, distracted fashion with Chelsea fans initially focusing on boo those opponents with English connections, Diego Forlan (Manchester United) and the subs Florent Sinama Pongolle (Liverpool) and Jose Antonio Reyes (Arsenal).
Atletico's fans, who had spent the afternoon busily shopping in Harrods and Hamleys, responded lustily, targeting the former Real Madrid striker, Nicolas Anelka, who was leading the Chelsea line as Didier Drogba completed the last game of his suspension.
Anelka was supported by Deco, loosely left-sided but roaming, and Kalou, who endured a hapless opening until finally getting his penalty-box SatNav working four minutes from the break. It was worth the wait as, his confidence strengthened, Kalou added a second seven minutes into the second period.
Chelsea had to resist some early pressure, during which Forlan and Sergio Aguero went close, before Ancelotti's men began to check on Atletico's well-known defensive vulnerabilities. They first had to journey through a vale of frustration.
When Lampard lifted in a free-kick from near the halfway line, Sergio Asenjo fisted the ball into his own net, much to the Bridge's delight and merriment. Chelsea's pleasure was short-lived, Kalou rightly ruled offside.
After a brief break for Ashley Cole to receive treatment after being struck by a Czech steam train called Tomas Ujfalusi, Chelsea pieced together a magnificent attack, bringing supporters to their feet, thrilled by the one-touch football, the speed and imagination. They then flung their hands into the air in despair at Kalou's finish.
What a waste. Deco's flick was sublime, transferring the ball into the path of Michael Ballack, who was gliding into the box. Germany's captain could have shot, really should have done in the light of Kalou's subsequent effort but he selflessly squared the ball. Kalou, unmarked, missed horribly, the ball hurtling apologetically a yard wide.
Consoled by Lampard, Kalou refused to wallow in self-pity and kept running, kept knocking at Atletico's shaky back-door which always looked ready to fall off its hinges.
Down the other end, a Forlan volley that stung Petr Cech's gloves provided a momentary scare but soon Chelsea were raiding forward again. Kalou had a shot saved by Sergio Asenjo and then, at last, found the mark. Lampard had been increasingly involved, clearly enjoying building moves from a deeper station, slightly to the left of the holding midfielder, Michael Essien.
Lampard, looking right to deceive Atletico's defence, delivered a reverse pass down the inside-left channel. Ballack cleverly let it run for the overlapping Ashley Cole, whose frequent trips to the Bridge deck following Atletico fouls had not dimmed his appetite for the forward gallop. Cole's cross was low and hard and Kalou simply could not miss, the Ivory Coast forward turning the ball into the net from five yards out.
Like the buses trundling down the Kings Road, the Bridge did not have long to wait for another Kalou goal. Seven minutes after the restart, Lampard swept over a corner that the unmarked Kalou headed easily in.
Still Chelsea looked for more. After exchanging passes with Essien 25 yards out, the outstanding Lampard beat Sergio Asenjo with a strong drive, ending the game as a meaningful contest. "Are you watching Liverpool?'' enquired the Matthew Harding Stand.
As Chelsea fans were flocking to the exits, disappearing merrily into the west London night, Ancelotti's side added a fourth, Perea accidentally heading in Malouda's free-kick. "Adios,'' chanted the remaining Blues fans.