Birmingham arrived at the Bridge with a painstakingly, proudly constructed record of 15 unbeaten matches. A wall of formidable resistance, surely? It met a wrecking ball.
Chelsea smashed them and, once more, sit handsomely on top of the Premier League pile. Lords of the manor. It was like a house of cards being disdainfully cuffed. And Joe Cole, dancing, jinking Joe on this form, was Chelsea's ace in the pack. A diamond performance.
Chelsea are now looking at home. The December blues have gone. A new year, a new hope. And all this, all these goals -- 16 in four matches -- confidence and belief are being gathered without Didier Drogba.
Chelsea struck within six minutes. The goal owed much to the skill of Joe Cole, working his way to the by-line down the right flank, easily past Lee Bowyer, and standing the ball up precisely inside the six-yard area for Florent Malouda simply to head back across Hart and into the net.
Chelsea then went even closer. John Terry released Joe Cole and after his cross was blocked, the corner was swung in by Malouda. Terry met it, beating Roger Johnson to the ball at the far post, but his header struck the frame of the goal and the rebound was hooked away.
By now, Chelsea were rampant. Ancelotti, understandably, had barely altered his team from the one which had demolished Sunderland so comprehensively in their last home league game, though Ashley Cole returned and Juliano Belletti was injured.
But Ancelotti had altered his formation, back to a more fluid 'box' in midfield, with greater movement to try to drag Birmingham out of position.
It was working, and again Hart was forced into a save, comfortably holding another Joe Cole effort. But Birmingham were facing wave after wave of attack.
The pressure told. And Joe Cole was again involved, skipping down the right before turning the ball inside to Michael Ballack, who swept it on to Frank Lampard who steadied himself and fired a crisp, low shot into the corner of the goal.
McLeish stood, shaking his head. His team had been unpicked, albeit by a team in rampant, relentless form, and their own efforts to find forward momentum were ponderous and hesitant.
But Birmingham returned to the fray after the interval with more purpose and finally sensed the opportunity to haul themselves back into contention and a gilt-edged chance fell to James McFadden. Clear on goal, he dragged his low drive wide.
They pushed on. A horrendous clearance by Ricardo Carvalho led to a rising toe-poke by Keith Fahey, which Petr Cech clawed over. Chelsea had the final say.
Malouda broke away and slipped a pass to the onrushing Lampard, who easily beat Hart with another low, assured shot. It was some display. (© Daily Telegraph, London)