Manchester United marched relentlessly towards the Premiership title as they recovered from a dreadful start to see off Middlesbrough's brave challenge.

The result sees the Reds extend their lead at the top of the table to 11 points and Sir Alex Ferguson's side now need only eight points from their remaining six games to claim a sixth title in eight years.

Bryan Robson had issued a tongue-in-cheek warning to his players not to score too early after the champions had trounced West Ham 7-1 after falling behind.

But to the delight of the home fans, 20-year-old Andy Campbell ignored his advice to fire Boro into an 18th-minute lead as the Teessiders dominated before the break.

But in the proverbial game of two halves, United blasted their way back into the game as Ryan Giggs produced a 46th-minute equaliser and then saw Andy Cole and Paul Scholes extend their lead in a devastating second-half display.

Paul Ince's 86th-minute header gave Boro same hope, but substitute Quinton Fortune looked to have sealed the win within a minute when he fired home from close range with the Boro defence claiming offside.

However, Brazilian Juninho set the alarm bells ringing for the visitors in injury time when he curled home a brilliant third goal to halt the leaving home fans in their tracks.

For all that the champions were awful before the break, they were irresistible for long periods after it, and with better finishing, the margin of victory could have been more comfortable.

The game became increasingly heated in the later stages and United skipper Roy Keane was withdrawn nine minutes from time after being booked as tempers frayed.

But it was Boro who left the pitch feeling aggrieved and still arguing with referee Paul Durkin over Fortune's strike, though TV replays showed the officials' decision to be correct.

The visitors spluttered through a first 45 minutes during which they spent long periods camped inside their own half and even when they managed to break free from the shackles imposed by the hard-working Teessiders, they squandered possession.

While Ince and terrier-like midfield partner Mark Summerbell spent the half snapping at the heels of their opponents, Keane was reduced to berating his team-mates for their inability to wrest the advantage from Robson's side.

From the moment Summerbell attempted to beat Mark Bosnich with an audacious back-heeled effort just two minutes into the game, it was clear that Boro were determined to emerge with all three points rather than a creditable draw.

Despite losing defender Colin Cooper through injury, the home side were in determined mood at the back, although Dwight Yorke should have put United in front with 18 minutes gone when he slipped in front of goal after Giggs had picked him out.

It was only a matter of seconds later when Campbell rocked the reigning Premiership champions when he latched on to Hamilton Ricard's ball over the top and volleyed through Bosnich's legs to open the scoring.

But the Australian keeper kept his side in it two minutes later when he parried a point-blank Brian Deane header.

For all that they were misfiring badly, the visitors could have ended the half in front after the unmarked Giggs headed high over from David Beckham's 35th-minute cross and then Cole fired high and wide three minutes later after Mark Schwarzer could only block Scholes' 20-yard effort.

The United players left the pitch knowing exactly what to expect from their manager at the break, but whatever he said had the desired effect within a minute of the restart.

Ince could only head Gary Neville's long throw to the edge of the box, where Giggs swivelled to fire right-footed past Schwarzer for the equaliser.

His team could have gone in front a minute later when Cole beat the offside trap but fired wide of Schwarzer's right post.

It was all United as the half unfolded, and Yorke failed by inches to get on the end of Giggs' driven 58th-minute cross.

Beckham then carved out an opening within two minutes as he raced away from Ince and Summerbell in the middle of the field before threading a pass into Cole inside the area.

The England striker needed no second invitation to collect his 22nd goal of the season, slotting his shot past the stranded keeper.

The Premiership leaders turned on the style, and Schwarzer had to get down well on 69 minutes to keep out a Scholes piledriver.

Boro desperately needed an injection, and a minute later Brazilian Juninho was sent on in place of Robbie Mustoe.

But the confidence had drained away from Robson's men, and it seemed only a matter of time before United increased their lead.

They did so 16 minutes from time as Scholes produced a vicious 25-yard shot which screamed past Schwarzer and into the top corner almost before the keeper could move.

United seemed to be coasting to victory, but Ince's near-post header from Juninho's corner and Fortune's goal maintained the interest level until the death.

Juninho gave his side a late lifeline with a brilliant curling shot past Bosnich in injury time, but the points were United's after a thrilling finish.

Teams:

Middlesbrough: Schwarzer, Fleming, Vickers, Cooper (Festa 12), Ziege, Deane, Mustoe (Juninho 70), Ince, Summerbell, Campbell, Ricard.

Subs Not Used: Beresford, Maddison, Stockdale.

Booked: Summerbell, Ziege, Ricard.

Goals: Campbell 18, Ince 86, Juninho 90.

Man Utd: Bosnich, G. Neville, Stam, Berg, Irwin (Silvestre 31), Beckham, Keane (Butt 81), Scholes, Giggs (Fortune 81), Yorke, Cole.

Subs Not Used: Sheringham, Van Der Gouw.

Booked: Keane.

Goals: Giggs 46, Cole 59, Scholes 74, Fortune 88.

Att: 34,775

Ref: P Durkin (Dorset).