David O'Leary ushered in the New Year in celebratory style as Mark Viduka and Robbie Fowler fired Leeds back to the top of the Barclaycard Premier League for the first time in six weeks.

Having watched championship rivals Liverpool and Chelsea suffer hangovers earlier in the day to pose further questions regarding their title aspirations, Leeds showed they are determined not to hand Manchester United another crown for Sir Alex Ferguson on a plate.

Written off just a few weeks ago, Manchester United are again favourites to clinch their fourth successive league trophy, and their eighth in the last 10 years, after a scintillating run of five straight wins.

Ferguson must have chuckled at Chelsea's collapse at Stamford Bridge, boss Claudio Ranieri's side losing 4-2 against Southampton, as well as Liverpool's latest slip in being held to a 1-1 draw against Bolton at Anfield.

Leeds had appeared to be heading in a similar direction prior to Christmas as they squandered five points from three successive matches at Elland Road, raising doubts about their own championship credentials.

But despite a crippling injury list - O'Leary without eight first-team players over the Christmas and New Year period in Harry Kewell, Olivier Dacourt, Seth Johnson, Dominic Matteo, Eirik Bakke, Robbie Keane, Michael Bridges and Lucas Radebe - the 43-year-old looked on as Leeds made it three wins in a row.

The return of the dynamic Lee Bowyer in midfield has undoubtedly been the catalyst, while Jonathan Woodgate's burgeoning partnership with skipper Rio Ferdinand at the heart of the defence cannot be understated.

But it is the dead-eye marksmanship of attacking duo Viduka and Fowler which is beginning to frighten the life out of opposing defences as they have scored 11 goals between them in the last five matches.

Viduka took his tally to 11 for the season with two goals in the opening seven minutes to knock any remaining Christmas stuffing out of the Hammers, who had come into the game on the back of a proud six-match unbeaten run to lift them away from the relegation zone and towards mid-table respectability.

In front of watching England coach Sven-Goran Eriksson, Fowler's place on the plane to Japan for this summer's World Cup finals will be guaranteed if he continues to show the maturity, composure and confidence which saw him score a sublime third for Leeds, and his sixth in those five games.

It means Leeds again sit proudly on top of the table - clear by two points - and will only be deposed from their lofty perch if Newcastle beat Manchester United at Old Trafford tomorrow night.

But the acid test of Leeds' drive for title glory will come over the next few weeks as games against rivals Newcastle, Arsenal, Chelsea and Liverpool all beckon.

On this form Leeds - Viduka and Fowler in particular - will take some stopping as they could easily have doubled this three-goal cushion but for inspirational Hammers goalkeeper David James, who will have helped his own England cause courtesy of several outstanding saves.

There was little James could do, though, as Leeds romped into the early two-goal lead, raising the temperature to warm the cockles on a bitterly cold night.

Crisp, enterprising passing on a clearly frosty Elland Road surface led to Bowyer and Fowler feeding Alan Smith down the right, the striker then floating in a superb cross for Viduka to guide past James from six yards after just 183 seconds.

Three minutes later Viduka again capitalised on another right-wing cross, this time from Danny Mills, the full-back dispossessing Nigel Winterburn and then providing a pin-point delivery for a flying Viduka to steal in front of Tomas Repka and power a bullet header beyond James.

The memory of conceding two-goal leads to both Leicester and Newcastle immediately before Christmas was still painfully fresh for Leeds fans, but their fears were eased five minutes after the break.

Viduka was the supplier on this occasion with a backheeled through ball for Bowyer as he made one of his typical runs, although the opportunity seemed to have gone when he failed to control on the edge of the area.

But the ball kindly ran to Fowler who produced a delicate, first-time chip over a stranded James to the delight of the majority of the 39,222 crowd.

Either side of what was the goal of the game, James defied Leeds with sensational saves from Viduka, Fowler - both denied potential hat-tricks - and Smith.

In contrast, Nigel Martyn was called into action only once and at a time when the points were safe, producing a fine tip over from a powerful 12-yard Repka header as Leeds made it three clean sheets in a row, returning to their previously frugal ways at the back to ensure they returned top with ease.

Teams

Leeds: Martyn, Mills, Ferdinand, Woodgate, Harte, Smith, Kelly, Batty, Bowyer (Wilcox 87), Viduka, Fowler.

Subs Not Used: Robinson, McPhail, Duberry, Singh.

Booked: Mills, Bowyer, Smith.

Goals: Viduka 4, 7, Fowler 50.

West Ham: James, Repka, Dailly, Schemmel, Winterburn, Cole, Hutchison, Moncur, Sinclair, Defoe (Todorov 75), Kanoute (Garcia 82).

Subs Not Used: Hislop, Foxe, Minto.

Booked: Repka, Kanoute.

Att: 39,320

Ref: S Dunn (Bristol).