Wayne Rooney scored Man Utd's winning goal in Yokohama
Wayne Rooney clinched victory for Manchester United in the Club World Cup final with a late goal against Liga de Quito after Nemanja Vidic was sent off.
Quito goalkeeper Jose Cevallos made a series of superb stops to deny Rooney, Carlos Tevez and Park Ji Sung in the first half as United dominated.
United's hopes were hit when Vidic saw red after 49 minutes for lashing out with an elbow at Claudio Bieler.
But Rooney won it with a neat finish into the bottom corner on 73 minutes.
There has been plenty of debate over the significance of this competition and the consequences that United's trip to the Far East will have on their domestic hopes and Champions League ambitions this season.
The immediate after-effects of their sojourn to Japan will be seen when they return to the Premier League action, and the less glamorous surroundings of Stoke City's Britannia Stadium, on Boxing Day.
But for now, United boss Sir Alex Ferguson can celebrate collecting the world crown to go with his side's Premier League and European titles secured earlier in 2008 - becoming the first English club to win the global event in its current format.
It should have been a far easier victory too, as United dominated possession from the start.
Quito's best chance came early on when Jairo Campos found space to meet Alejandro Manso's whipped free-kick in front of goal but somehow put his shot wide.
But the South American champions were on the back-foot from that point onwards and were grateful to Cevallos for three good saves in the first 20 minutes.
Cevallos did well to push away a Rooney snap-shot from the edge of the area and repeated the trick to keep out another ferocious effort from the England striker soon after - although this time he will have been relieved that the ball bounced wide after it had span from his grasp.
And the 37-year-old was soon in action again, flinging himself to his right to keep out a diving header from Tevez after some good work from Cristiano Ronaldo.
Ronaldo looked keen to impress the crowd at the Yokohama International Stadium, showing off some fancy footwork at every opportunity, with only an end-product missing from his play.
United's failure to score was not through lack of effort, or chances, and Cevallos was again in the right place at the right time to palm away Park's stinging shot before parrying another effort by Tevez.
Park should have done far better before the break when Anderson's long ball fell to him at the back post - but he miscued horribly and sliced his attempted chip well over.
It looked like Ferguson's men would be punished for failing to take those chances when Vidic was dismissed for his clash with Bieler with both players grounded - and the red card also means he will be suspended for the first leg of United's Champions League clash with Inter Milan in February.
United celebrate after Wayne Rooney's second-half winner
United's 10 men were forced to reshuffle and Tevez was replaced by Jonny Evans, who filled in at the back.
But it made little difference to the pattern of the game as Quito still lacked ambition and United continued to come forward.
Edwin van der Sar did have to claw away a long-distance shot by Manso but it was the English side who looked more likely to break the deadlock.
Rooney and Ronaldo had been by far the best performers on the day and they combined to deadly effect with 17 minutes left.
The Portuguese winger teed up Rooney on the left-hand corner of the penalty area to bury a low shot in the far corner of the net.
Quito, at last, attempted to respond but the closest they came to an equaliser was another effort from range by Manso that Van der Sar tipped over.
Earlier on Sunday, Japan's Gamba Osaka secured a third-place finish with a 1-0 win over Mexican side Pachuca.
Liga Deportiva : Cevallos, Norberto Araujo, Calle (Ambrossi 77), Campos, Calderon, Reasco (Larrea 82), Urrutia, William Araujo, Manso, Luis Bolanos (Navia 87), Bieler.
Subs Not Used: Dominguez, Obregon, Delgado, Eder Vaca, Danny Vaca, Chango, Viteri.
Booked: Bieler, Campos, Cevallos, Calle, William Araujo.
Man Utd: Van der Sar, Rafael Da Silva (Neville 85), Ferdinand, Vidic, Evra, Ronaldo, Carrick, Anderson (Fletcher 87), Park, Tevez (Evans 51), Rooney.
Subs Not Used: Kuszczak, Berbatov, Giggs, Nani, Scholes, Welbeck, O'Shea, Gibson, Amos.
Sent Off: Vidic (49).
Goals: Rooney 73.
Ref: Ravshan Irmatov (Uzbekistan).
BBC Sport Player Rater man of the match: Manchester United's Wayne Rooney 7.86 (on 90 minutes).
Please note that you can still give the players marks out of 10 on BBC Sport's Player Rater after the match has finished.