Middlesbrough 1 Manchester United 2:Manchester United winger Cristiano Ronaldo plunged himself into further controversy as the Barclays Premiership leaders claimed three points at Middlesbrough.

Referee Chris Foy awarded the visitors a 19th-minute penalty after Ronaldo had gone down under keeper Mark Schwarzer's challenge, although replays suggested the anger of the home fans was justified.

Frenchman Louis Saha exorcised the ghost of his Champions League miss against Celtic by sliding home the spot-kick, although his effort was not the game's decisive intervention.

United went close to extending their lead on several occasions, but they were pegged back on 66 minutes when substitute James Morrison dragged the Teessiders right back into it.

However, Sir Alex Ferguson's men needed less than two minutes to restore their advantage, Darren Fletcher heading home the winner to cement his side's lofty status in front of a crowd of 31,238 as the master got the better of novice Gareth Southgate.

Had United not won they would have had only themselves to blame, although the Boro boss will have been pleased with the attitude of his players after he was forced into a half-time reshuffle by Jonathan Woodgate's premature departure.

Boro welcomed winger Stewart Downing back from a groin injury, and combative midfielder Lee Cattermole as well.

However, neither proved to be the central figure in an opening 45 minutes packed with both incident and controversy.

That United deserved to leave the pitch at the break to the good after a series of high-octane attacks was not in any doubt, but the way in which they achieved it left a sour taste in the mouths of the home fans.

The visitors had already gone close twice - Saha saw a downward header blocked on the line by Robert Huth, and Ryan Giggs failed to find an empty net after Schwarzer had parried Ronaldo's blistering strike - when they got their noses in front on 19 minutes.

United's approach play was little short of breathtaking, Saha turning just inside the Boro half to race past Woodgate and slide a precision pass into the path of the unmarked Ronaldo.

The Portuguese international took the ball in his stride and cut inside Schwarzer, plummeting to the ground in the process.

Referee Foy pointed immediately to the spot, but what contact there was, if any, was minimal. Saha, taking a penalty for the first time since his costly European miss at Parkhead, stroked the spot-kick past the Australian to make it 1-0.

The Teessiders might have been level within two minutes, Abel Xavier hitting a post with a header from Downing's free-kick in his first home game since his drugs ban expired.

But Wayne Rooney, who endured a quiet evening, steered a shot just wide at full-stretch 11 minutes before the break and Schwarzer had to tip a rasping 40th-minute Ronaldo free-kick over as United threatened to kill the game off.

Woodgate's non-appearance after the break saw Southgate abandon his 3-5-2 formation for a more orthodox 4-4-2 with Morrison coming on to line up on the right side of midfield.

The new shape gave the home side a more enterprising look, although central defender Huth wasted a promising position when he drilled an ambitious 51st-minute free-kick straight into the wall.

Schwarzer had to turn a dipping left-footed shot from Ronaldo around the post two minutes later, but Edwin van der Sar was called upon for the first time in the game seconds later to pluck a Morrison cross out of the air just ahead of Aiyegbeni Yakubu.

But Boro were looking increasingly vulnerable and Giggs shot high and wide from a tight angle after Paul Scholes and Rooney had staged a scintillating break-out before Huth had to dispossess the England striker in front of goal.

They were made to pay with 66 minutes gone when Downing cleverly evaded Gary Neville's challenge to cross and Gabriel Heinze's weak header fell to Morrison, who thumped a volley past van der Sar to level.

But the home side's joy was short-lived and ended within two minutes as Giggs picked put Fletcher's run into the box after Ronaldo had left the Boro defence standing and the Scot headed powerfully home.

Downing curled an 85th-minute free-kick past the angle of bar and Huth saw a late effort hacked away by Neville, but the points were safe.