Paul Scholes scored his 100th Manchester United goal to keep the title fires burning at Old Trafford but it might be the ones that got away which eventually turn the season into a damp squib.

There could be no doubting the Red Devils' dominance, especially after stand-in keeper Ricardo capped a remarkable Premiership debut with a penalty save just two minutes after his half-time introduction for Fabien Barthez.

However, with Arsenal matching United's margin of victory at the Riverside, Sir Alex Ferguson may yet come to regret his team's profligacy in front of goal.

Ryan Giggs, Ole Gunnar Solskjaer, Scholes and goal-king Ruud van Nistelrooy all spurned clear chances. And while the prolific Dutchman did take his tally for the season to 38 when he opened the scoring with a superb far post header from David Beckham's cross, United know they would still be behind on goal difference should Arsenal wipe away the Red Devils' three-point lead by winning their vital game in hand.

The ruthlessness required to operate at such a rarified atmosphere in the football world was in evidence again as Ferguson tried to balance the pressing need for points with the looming Champions League return against Real Madrid.

Having launched a passionate defence of Solskjaer in the wake of Sol Campbell's dismissal in the championship showdown at Highbury, the United boss promptly dropped his Norwegian star to the bench as David Beckham returned to league combat after a three-match absence.

Solskjaer was in good company as also among the substitutes were Roy Keane and Gary Neville, who appears set for a lengthy stint out of the side as brother Phil was named at left-back in John O'Shea's absence as Wes Brown continued on the right.

For the best part of 15 minutes, the game meandered along, Blackburn confident enough on the back of six wins from their last seven outings to take United on as Ferguson had hinted they might.

Quinton Fortune, making only his second Premiership start since the beginning of December, did have one shot blocked but generally, it was the home defence which looked most uneasy and even after van Nistelrooy had scored his ninth goal in five games, Blackburn continued to look dangerous.

Damien Duff is a reported summer transfer target for United and his mazy runs were certainly attracting the attention of some startled defenders and when Beckham lunged in to send the Irishman flying, the punishment came not in a yellow card but an equalising goal.

In four seasons as a Red Devil, Henning Berg scored just two league goals, yet when Fabien Barthez lost the flight of David Dunn's cross, the veteran Norwegian defender rose virtually unchallenged to nod home.

The goal was greeted with stunned amazement by the vast majority of another capacity crowd and for a while Blackburn threatened to take control, Barthez at one stage being called on to make an acrobatic stop after Rio Ferdinand had smashed an attempted clearance into Nicky Butt's back.

It wasn't that United weren't creating opportunities, just that they were spurning too many. Van Nistelrooy rolled shots just past both posts, then Craig Short blocked off a Giggs' square ball to the Dutchman as United looked to exploit an overlap on the break.

Short, though, could do little to avoid diverting the ball into Scholes' path shortly before the interval after an excellent left-wing burst to the by-line from Neville and the ginger-haired maestro is not one for wasting the opportunity to blister the net from 10 yards.

If the end of the first half had been high-octane excitement, the start of the second was super-charged, especially for Ricardo, who had replaced Barthez in the United goal.

The Spaniard did not take the hint when Rio Ferdinand eased off when chasing Andy Cole back, came out far too late and sent the former United favourite crashing inside the area.

Eager to make amends, Ricardo promptly flung himself to the left to beat out David Dunn's penalty, in the process providing the home side with the impetus to stretch their advantage.

Giggs should have done it when he burst clear after taking Scholes' pass in his stride, only to drive a poor shot straight at Freidel.

However, the Welshman was up for the challenge, robustly diving in to rob Cole after Fortune had been dispossessed, then setting van Nistelrooy away with an instant pass.

Fearing the angle was too acute even for him, the Dutchman intelligently continued to the by-line where his low cross was bundled home by United's newest century-maker.

Chances went begging after that, Van Nistelrooy missing a couple, as did Giggs and Solskjaer, who made his belated appearance eight minutes from time.

When the final totals are added up, how crucial those misses could prove.

Teams

Man Utd: Barthez (Ricardo 45), Phil Neville, Ferdinand, Brown, Silvestre, Beckham, Butt (Keane 54), Scholes, Fortune, Giggs (Solskjaer 83), van Nistelrooy.

Subs Not Used: Gary Neville, Forlan.

Goals: van Nistelrooy 20, Scholes 42, 61.

Blackburn: Friedel, Neill, Berg (Taylor 64), Short, Gresko, Dunn, Tugay, Flitcroft, Duff (Sukur 66), Cole, Yorke.

Subs Not Used: Kelly, Grabbi, Todd.

Goals: Berg 24.

Att: 67,626

Ref: A D'Urso (Essex).