Ole Gunnar Solskjaer could hardly have timed his hat-trick better as Manchester United eased four points clear at the top of the Premier League.

Solskjaer knows his new position as Ruud van Nistelrooy's strike partner is under serious threat following the arrival of Diego Forlan.

The Uruguayan had impressed Sir Alex Ferguson so much in training since his £7.5million move from Independiente last week that the United manager brought forward his debut by a week.

However Solskjaer is in no mood to step aside after clawing his way up the strikers' pecking order at Old Trafford and he threw down the gauntlet to his new rival in emphatic style.

Ferguson punched the air with delight when Solskjaer completed his hat-trick, which took his tally for the season to 13, and well he might as the Norwegian had earned United three precious points.

Ferguson had been desperate to win this game following back-to-back defeats against Liverpool and Middlesbrough had given their title rivals fresh hope.

He will have been delighted by this victory, with a performance more like the United who had strung eight league wins together before that Liverpool defeat.

It had all looked so different at the start when in front of a record Reebok crowd of 27,350, Bolton began determined to repeat their famous 2-1 win over United at Old Trafford.

Bolton, whose last league win was back on November 18, tore into the Reds with all the gusto of the recent gales that have battered Britain this week.

Fredi Bobic, who had a night to forget, shot wide from a great opening at the near post before Fabien Barthez saved from Michael Ricketts.

United weathered this early storm and then opened the scoring on 15 minutes from a classic counter-attack.

Ruud van Nistelrooy sent the irrepressible Ryan Giggs haring down the left and he squared the ball to Solskjaer, who tucked it home inside the far post.

United took charge after the goal and David Beckham went close to adding a second when he flashed a 20-yard free-kick across the face of the goal after Ricardo Gardner had been harshly penalised for a challenge on Paul Scholes.

Then Mikael Silvestre found Giggs in the box and the Welshman spun round and hit a shot, which Jussi Jaaskelainen almost fumbled into his own net.

United kept up the pressure and Jaaskelainen parried a Roy Keane drive and Gardner hooked the rebound away from Beckham.

But that only postponed the inevitable and from the resultant corner in the 38th minute, Solskjaer glanced home Beckham's centre from the edge of the six-yard box.

It was exhibition stuff now from United and Giggs headed wide in a disappointing culmination to a lovely flowing move.

Despite United's superiority, Wanderers almost pulled a goal back on the stroke of half-time when Barthez saved Ricketts' powerful point-blank volley.

Normal service was restored after the break and the outstanding Giggs hit a shot against the upright inside the opening 10 seconds

Bolton threatened again, only to find Barthez in no mood to be beaten and the Frenchman made a stunning one-handed save to keep out Ricketts' header from substitute Simon Charlton's deep cross

Solskjaer finished Bolton off on 64 minutes when he completed his first hat-trick for United since December 1999 with a goal which was a near replica of his first.

Again Beckham was the provider and he swung over a free-kick for the Norwegian to glance home a header.

With victory assured, Ferguson took off Laurent Blanc, Roy Keane and Solskjaer and Forlan replaced the latter to make his debut.

On the evidence of Solskjaer's finishing, Forlan knows he faces a mammoth challenge to win a regular starting place in United's attack.

And that's without mentioning van Nistelrooy, who, after missing a sitter, sidefooted home United's fourth, and his 24th of the season, from Giggs' centre to complete the scoring seven minutes from time.

Teams

Bolton: Jaaskelainen, Southall (Charlton 45), Bergsson, Whitlow, Gardner, Hansen (Johnson 59), Nolan, Barness, Farrelly, Bobic (Holdsworth 75), Ricketts.

Subs Not Used: Poole, Pedersen.

Man Utd: Barthez, Phil Neville, Gary Neville, Blanc (O'Shea 72), Silvestre, Beckham, Keane (Butt 73), Scholes, Giggs, Solskjaer (Forlan 76), van Nistelrooy.

Subs Not Used: Carroll, Brown.

Goals: Solskjaer 15, 39, 64, van Nistelrooy 84.

Att: 27,350

Ref: A D'Urso (Billericay).