"Top of the league that's a fact," sang the fans of Manchester United with a nod to Rafael Benitez's famous David Brent-esque tirade but the point about their side's title credentials was made most emphatically on the pitch. Five goals and United's 11th consecutive clean-sheet in the league equals title-winning form. Over to you, Liverpool.
Paul Robinson's red card was the game's most contentious point but it would be wrong of West Brom to argue that it was pivotal. Even before their captain was dismissed by referee Rob Styles five minutes before half-time, United looked comfortable – against 10 men, the figurative cigars were being lit. The last two of their five were scored by Cristiano Ronaldo, his first goals in the league since 15 November, who at last looks like he might be interested.
For United, it is, as Ferguson said "coming together at a good time" with their biggest away win since the 8-1 drubbing of Nottingham Forest in February 1999. The United manager said: "March and April is where it matters, we have shown a bit of a ruthless streak which hasn't been there this season. We always believed it would come because of the standard of forwards we have."
Dimitar Berbatov, Carlos Tevez and Nemanja Vidic scored the others as United put three points between them and second-place Liverpool, who play Wigan tonight. Edwin van der Sar's 11th clean sheet meant that, in the 84th minute, he surpassed Petr Cech's Premier League record of 1,025 consecutive minutes without conceding. If he holds out for another 72 minutes against Everton on Saturday he will have beaten the overall record in English football held by Reading goalkeeper Steve Death.
"Van der Sar, who has achieved everything in the game, is as delighted as when saved that penalty in Moscow [against Chelsea in the Champions League]," Ferguson said. "He has that ambitious streak in him."
The only consolation for Benitez is that West Brom's complaints about Styles' red card for Robinson means that the Liverpool manager now has an ally in his conspiracy theories about favouritism towards the champions.
West Brom were already one goal down and doing their best to hold United when Robinson slammed into Park Ji-Sung as both men went to ground in pursuit of the ball. The left-back's left boot was only slightly raised but with that glimpse of studs, and the ferocity with which he came at Park he gave Styles an invitation to send him off. Robinson's challenge was not as gruesome as some but he was not in control of the tackle when he collided with Park.
Ferguson described it as "careless and reckless". "They tell me that from the other television angle it doesn't look as reckless but I have to say it was a careless challenge," Ferguson said. "He didn't need to do it, the boy slid into him. At 10 men and 1-0 down it was difficult for them and with the experience we had on the pitch it was going to be hard."
Tony Mowbray said that he would consider appealing although his greatest worry must be that with Robinson now suspended for three games he is without 12 players and bottom of the league. "If the television replay shows he did not leave the ground, he did not show his studs and that it was just a collision between two players then there is a pretty good cause for an appeal."
Amid the subsequent fury unleashed from the stands towards Styles, something was thrown at the referee as he approached the touchline to book Robert Koren a few minutes later. From that free-kick, a minute before the break, West Brom conceded their second goal. Scott Carson dropped Ryan Giggs' cross and Tevez scored. Before then Berbatov had got the first after an exchange with Michael Carrick.
Before Vidic added United's third on the hour, West Brom had the glimmer of a chance when their centre-back Ryan Donk struck a sweetly-hit shot that cannoned off the post. After that United made no mistakes, Vidic powering through the penalty area to head in United's third from Giggs' corner. The fourth goal was beautifully worked, Giggs in midfield playing in Tevez, who laid off for Ronaldo to score. Berbatov provided the fifth for Ronaldo, who finished from close range.
Goals: Berbatov (22) 0-1; Tevez (44) 0-2; Vidic (60) 0-3; Ronaldo (65) 0-4; Ronado (73) 0-5.
West Bromwich (4-4-2): Carson; Hoefkens, Donk, Pele, Robinson; Zuiverloon (Morrison, 64), Valero, Koren, Brunt; Simpson (Bednar, 64), Fortune (Cech, h-t). Substitutes not used: Kiely (gk), Kim, Dorrans, Teixeira.
Manchester United (4-4-2): Van der Sar; Neville (Eckersley, 71), Ferdinand (Brown, 70), Vidic, O'Shea; Park, Carrick, Giggs, Ronaldo; Berbatov (Tosic, 77), Tevez. Substitutes not used: Kuszczak (gk), Scholes, Fletcher, Gibson.
Referee: R Styles (Hampshire).
Booked: West Bromwich Koren, Carson, Donk, Bednar, Morrison; Manchester United Park, Carrick.
Sent off: West Bromwich Robinson (40).
Man of the match: Berbatov.
Conceding nothing: United set defensive record
Manchester United last night set a new Premier League record for minutes without conceding, an 11th successive Premier League shut-out surpassing Chelsea's record of 1,025 minutes without conceding. Petr Cech did not concede between Thierry Henry's 29th-minute goal in a 2-2 draw at Arsenal in December 2004 until Leon McKenzie's goal for Norwich three months later.
United's 11 games
15 Nov 08 Man Utd 5 Stoke 0
22 Nov 08 Aston Villa 0 Man Utd 0
30 Nov 08 Man City 0 Man Utd 1
6 Dec 08 Man Utd 1 Sunderland 0
13 Dec 08 Tottenham 0 Man Utd 0
26 Dec 08 Stoke 0 Man Utd 1
29 Dec 08 Man Utd 1 Middlesbro 0
11 Jan 09 Man Utd 3 Chelsea 0
14 Jan 09 Man Utd 1 Wigan 0
17 Jan 09 Bolton 0 Man Utd 1
27 Jan 09 West Brom 0 Man Utd 5
The Arsenal midfielder Samir Nasri was the last player to score a league goal against United, his 48th-minute winner during a 2-1 victory at the Emirates on 8 November 2008.