Gudjohnsen, starting up front instead of 18-year-old Cole, hit the net twice - and Gianfranco Zola scored a cracker to clinch a 3-0 interval lead.

Chelsea stormed into a two-goal lead through a virtual carbon-copy goal with 31 minutes on the clock.

Kenna, switched from right-back to the left side of defence to counter Sadler’s absence, was again at fault.

Zola slotted a superb 30-yard pass between the out-of-position Birmingham skipper and centre-back Kenny Cunningham – and Gudjohnsen again dispatched the ball into the bottom left corner.

Ranieri’s side were rampant now, with Lampard sending a 22-yard drive skidding a foot wide of the left post 60 seconds later, with Vaesen bemusingly making no attempt to save the ball.

Zola also sent an angled drive past the same upright – and forced Vaesen into a smart near-post parry as the Londoners tore Bruce’s team apart.

Number three was inevitable and arrived four minutes before the break. Zola attempted to play a return pass to Le Saux, but the ball hit Cunningham and rebounded to the Italian – who smashed home a thunderbolt drive, again into the bottom left corner.