In his 801st match for United, Ryan Giggs scored the opener on 25 minutes. The Welshman received a pass from Nemanja Vidic and netted from just outside the penalty area.
And the second goal came six minutes after the break as Korean Ji-Sung Park's sent the ball past keeper Jones following preparing work from Wayne Rooney.
It was not a match of many chances but United did dominate the way they had to, in order to secure a professional 0-2 win.
MIDDLESBROUGH (AFP) - Sir Alex Ferguson has warned Manchester United's title rivals they are running out of time to catch the Premier League leaders.
Goals from Ryan Giggs and South Korea winger Park Ji-Sung sealed an easy 2-0 win at Middlesbrough to extend the European Champions' advantage to a commanding six points with just four games remaining.
Liverpool could close the gap to three points with a victory over Newcastle at Anfield on Sunday, but United have a game in hand against Wigan, ensuring they remain firmly in the driving seat.
United could not have asked for an easier warm-up for Tuesday's Champions League semi-final second-leg at Arsenal as they strolled to a fifth consecutive league victory to move a significant step closer to a record-equalling 18th English title.
Liverpool and Chelsea remain in pursuit in case of any late slip-ups as United chase a third consecutive title, but Ferguson remains fully confident of leading his side to further silverware.
He insisted: "This is a big step forward towards retaining the title. I keep saying that if you whittle the games away, eventually there are no games left and hopefully we'll get to that position in a couple of weeks."
The result was never in doubt after Giggs' strike midway through the first-half, confidently swept home left-footed from the edge of the box for the midfielder's fourth goal of the season to increase the pressure on relegation-threatened Middlesbrough.
It capped a memorable few days for the newly crowned Professional Footballers' Player of the year, who made his record-breaking 800th appearance for the club in midweek.
Giggs said: "It's been a great week, and it couldn't have gone better really. I won the award, made my 800th appearance and then scored against Middlesbrough."
Despite their dominant position, Giggs refused to accept United's latest title is already in the bag.
He added: "We always had this penciled in as a tough game because we struggled here last year so we just wanted to get this one out of the way.
"We've done that and now and we've just got to concentrate on the remaining games because Liverpool are a good side and it will go right to the end."
Park's angled drive soon after the re-start from Wayne Rooney's sublime slide-rule pass sealed victory against Boro, whose best chance came early on when forward Jeremie Aliadiere shot against the legs goalkeeper Ben Foster, one of seven United changes as Ferguson shuffled his pack ahead of the Arsenal showdown.
The Scot, whose side looked fresh despite clocking up a 60th game of the campaign, added: "With the position that Middlesbrough are in we knew it would be a battle and that they'd come at us early on.
"But once we got hold of the ball we always looked a danger. Getting in front was the key, that sealed the victory."
Middlesbrough have just three games left to stage an unlikely escape from the bottom three, and face a make-or-break trip to relegation rivals Newcastle when they return to action on May 11, with the loser all but certain to be doomed to the drop.
A first home defeat for for more than four months leaves them second from bottom and after just two victories in their last 23 league games, the Teesside club need to show a vast improvement if they are to extend their 11-year stay in the top flight.
Manager Gareth Southgate admitted: "We've been in the bottom three for a long time now and we know we have to go to Newcastle and win. We have to handle the atmosphere there and it's the last throw of the dice.
"We needed to score first against United and even though the goals we conceded weren't very good from our point of view, in truth we were beaten by a better team."
When asked if he sees anyone catching United at the top, Southgate added: "I don't think so."
MIDDLESBROUGH (AFP) - Manchester United extended their lead at the top of the Premier League to a commanding six points as goals from Ryan Giggs and Park Ji-Sung sealed a comfortable 2-0 win away to Middlesbrough.
Giggs struck his fourth goal of the season before the break here at the Riverside Stadium on Saturday to help double United's points advantage over title rivals Liverpool, who host Newcastle on Sunday.
And South Korea international Park deservedly doubled their advantage early in the second-half as reigning champions United, seeking to equal Liverpool's record of 18 English titles, strolled to a fifth consecutive league victory.
United couldn't have asked for an easier warm-up for Tuesday's Champions League semi-final trip to Arsenal, where they defend a single-goal first-leg lead, as they showed little sign of fatigue despite clocking up their 60th game of a season that could yet see them win four trophies.
Despite United winning at a canter, there had been little to choose between the teams before Giggs - almost a week after his peers the Professional Footballers Association (PFA) voted him player of the year - broke the deadlock midway through the first-half.
Middlesbrough's Jeremie Aliadiere spurned the best chance to open the scoring, when he saw his shot blocked by the feet of goalkeeper Ben Foster after the forward, under pressure from defender Nemanja Vidic, had been put through by Marlon King.
Giggs, one of seven United changes from the team that started in the 1-09 Champions League victory over Arsenal on Wednesday, showed the Frenchman how it should be done after 25 minutes.
The former Wales international produced a clinical finish left-footed into the bottom corner from 20 yards after Federico Macheda had squared England striker Wayne Rooney's centre back across the edge of the area.
Middlesbrough appeals that Dimitar Berbatov fouled Matthew Bates as the ball made its way through to Giggs were ignored by referee Mark Halsey as United sealed a third league and cup victory over Boro this season.
Macheda should have doubled the advantage straight after the break when Rooney beat Tony McMahon to provide an inviting cut-back, only for the teenage striker to poke the chance wide at the near post from five yards.
United didn't have long to wait for their growing dominance to be rewarded as Park claimed their second in the 51st minute.
Rooney was again the architect, with a sublime slide-rule ball into the area which wrong-footed the Middlesbrough defence to allow Park to fire home his third goal of the season from 12 yards past stranded keeper Brad Jones.
Only a desperate late block from Bates, the hosts' best player, prevented John O'Shea - the goalscorer from Wednesday's Champions League clash - from adding a third from close range inside the last 10 minutes as Boro left gaps at the back in a fruitless bid to find a way back into the contest.
A first home defeat for more than four months left Middlesbrough second from bottom and three points adrift of safety with just three games remaining, starting with the crucial derby trip to Newcastle on May 11.
But after just two victories in their last 23 league games, the Teesside club need to show a vast improvement in form if they are to extend their 11-year stay in the top flight.