Leeds boss David O'Leary's "young babies" cemented their place in the United record books alongside Don Revie's legendary side of the early 1970s.

A rampant first-half comeback performance guaranteed Leeds their sixth successive victory, the first time they have achieved such a feat in the top flight since Revie guided United to the old First Division title in 1974, the last time Derby won at Elland Road.

The win also pushes United into third place in the Premiership, ahead of Chelsea who face Aston Villa tomorrow morning, and with it the final coveted Champions' League slot.

O'Leary only recently admitted his side would not go any higher than fourth because they could not compete with the larger squads of Manchester United, Arsenal and Gianluca Vialli's club.

But the Leeds players appear determined to prove their manager wrong, even if they may only be third for 21 hours given the result at Villa Park.

The result has also dented Derby's own dreams of Europe and ended the recent revival under boss Jim Smith which had seen the Rams move up to sixth.

For Smith, the first-half was all one-way after Francesco Baiano had given Derby a fourth-minute lead from the penalty spot. Leeds skipper Lucas Radebe uncharacteristically and needlessly scythed down Derby's debut-making Greek wing-back Vas Borbokis as he made an instant impact.

The former Sheffield United star had arrived at Pride Park in a £1.1million deal which saw Jonathan Hunt and Robert Kozluk plus £500,000 head to Bramall Lane.

Birmingham referee Mike Reed, who on his last visit to Elland Road booked 13 players during a goalless draw with Chelsea back in October, had no hesitation in pointing to the spot.

After almost 90 seconds of treatment for Borbokis, Baiano then sent Nigel Martyn the wrong way from 12 yards for his fifth of the season. It was a vital early lift for a Derby side riddled by injury and suspension, but it was the closest they came towards seeing the whites of Martyn's eyes again for the rest of the game.

Leeds were again irresistible and unstoppable as they swept the Rams aside over the course of the next 40 minutes with three fully deserved goals. Winger Willem Korsten, who looks certain to be signed by O'Leary in the summer when his loan spell from Vitesse Arnhem comes to an end, signalled United's intent with a 15-yard left-foot drive which was narrowly wide of recalled keeper Mart Poom's left-hand post.

Within two minutes Leeds were level when Bowyer beat Poom with a second bite of the cherry after Spencer Prior had blocked his first side-foot effort following Hasselbaink's cross from the right.

The Dutch international followed up his free-kick special at Sheffield Wednesday last week with another sublime dead-ball drive for United's second. Prior was called for a foul on Harry Kewell on the edge of the D by Reed allowing Stephen McPhail - in the side for flu victim David Batty - and David Hopkin to tee up 'hot-shot Hass' for a low curler round the wall and into the bottom left-hand corner of Estonian international Poom.

Derby's problems increased five minutes before the break when an accidental collision with Kewell led to influential captain and centre-back Igor Stimac being carried into the dressing room.

United took advantage of a Derby side down to the barte bones. Hasselbaink was again the supplier, this time with a neatly-flicked through ball to fellow Dutchman Korsten from the left wing.

Korsten was in the act of falling on his backside when he just managed to squeeze an acutely-angled left-foot shot beyond Poom.

Leeds took their foot off the gas in the second half, but were still comfortably in control, proven by a fourth in the 85th minute and the goal of the game.

Left-back Ian Harte cut across the Derby area and when the opportunity arose, the Republic of Ireland international let fly with a screaming 22-yard right-foot shot which flew into Poom's top left-hand corner.

Another rapturous round of applause from a 39,000 crowd echoed around Elland Road at the final whistle on a result which moves Leeds eight points clear of fifth-placed West Ham.

Teams

Leeds: Martyn, Haaland, Radebe, Woodgate, Harte, Hopkin, Bowyer, McPhail, Korsten (Jones 88), Hasselbaink, Kewell.

Subs Not Used: Wetherall, Ribeiro, Halle, Robinson.

Booked: Haaland, Hopkin.

Goals: Bowyer 18, Hasselbaink 32, Korsten 45, Harte 85.

Derby: Poom, Prior, Carbonari, Stimac (Elliott 40), Borbokis, Bohinen (Launders 78), Powell, Laursen, Baiano (Christie 46), Harper, Burton.

Subs Not Used: Robinson, Hoult.

Booked: Baiano, Prior.

Goals: Baiano 4 pen.

Att: 38,971

Ref: M Reed (Birmingham).