Birmingham 0 Liverpool 3
Heskey laid on the first for Michael Owen before slotting home himself to seal victory for Liverpool at St Andrews - and showcase his talents ahead of the European Championship in the summer.
Compatriot Steve Gerrard looked at his awesome best and he added a third on 85 to cap a scintillating display with a deserved goal.
The powerful striker had started poorly, hedging his bets between a cross and shot and achieving neither with Owen poised to finish.
However, after Owen had overrun a second good chance to open the scoring, Heskey's through ball set the England international scampering towards goal.
Under pressure from Kenny Cunningham, and with goalkeeper Ian Bennett racing out, Owen calmly rolled the ball into the far corner with the outside of his right foot to give the hosts a deserved lead.
Birmingham have suffered a major dip in form of late, and looked unlikely to forge a way back into the game - and when Heskey added a second at the beginning of the second half - it left Steve Bruce's men with a monumental task.
Gerrard - registering another driving performance that will warm English hearts ahead of Euro 2004 - was the architect powering down the right and cutting back.
Heskey had the narrowest of angles to aim at, but when given little time the former Leicester man can show an astute instinct and his finish was top quality.
A monumental task soon became an impossible one, when Cunningham received his marching orders for a professional foul on Gerrard.
The midfielder showed the greater desire to drive onto a loose ball past the defender, and when minor contact felled Gerrard, referee Steve Dunn did not hesitate in showing a red card.
Heskey nearly added a second to his personal tally when he latched onto a cutback from Owen, and the diminutive striker also missed a glorious opportunity when played in by Gerrard.
Owen was played in superbly by his captain, but opted to round keeper Bennett and his first touch, not for the first time, was heavy and allowed defenders back to cover.
Harry Kewell drove wide when he could have opted to pass, but Gerrard finally did extend the lead when he again broke down the left and cut back across the penalty area before picking out the far corner to show how important he is to the Liverpool challenge.
There was still time for Owen to waste a glorious chance to make the score more emphatic, but it mattered little to the delighted travelling fans.
Liverpool are now three points clear of Aston Villa in fifth - although Newcastle United have two games in hand and could go level to make the final week's clash against The Reds a classic six pointer.
