Rooney's blaze of glory outshone by old master

First, take a deep breath and forget about the current goalscoring phenomenon, Wayne Rooney. The moment of real wonderment at Old Trafford on Saturday was one of the evening's last, delivered when Ryan Giggs, all 34 years and 11 months of him, chased 70 yards to place the tackle which halted Ishmael Miller's advance into the penalty area. He then promptly belted the ball 40 yards, wing-to-wing, beginning the move which ended with Manchester United's fourth goal.

This was the same Giggs who was on the phone to Paul Ince a few weeks back, ruminating over how he "can't keep playing for ever" and who was characterised as the venerable old "silver streak" in a United match programme last winter. West Bromwich's Jonathan Greening, whose three-year Old Trafford career saw him into the same 1999 Champions League final squad as Giggs, certainly didn't miss the significance of the 88th-minute cameo. "Seven hundred-odd games here and he's still doing the business and he's still going strong," Greening said. "He's some pro, some player."

The point is that age can defy expectations in football. At the other end of the scale, Ferguson rationalises that Rooney will move beyond his current goal spurts, much like a teenager gets beyond growth spurts, and come to score consistently. But will he? Rooney's done his growing, his hairline is moving in the wrong direction and Ferguson might just have to settle for what he's got – a player who burns like the fury, extinguishes himself and renews. Rooney's total contribution as United's three goals in 15 minutes exposed West Bromwich's defensive naivety were as pure an illustration as you'll ever find that any comparisons Ferguson hopes might one day be made between him and that consistent penalty box king Gary Lineker will never come to pass.

On evenings like this, the debates about playing Rooney through the centre are equally fatuous, as Greening also pointed out. "It simply doesn't matter where Alex Ferguson plays him," the Albion captain said. "If he's getting joy down the left, he'll go there and if he's getting joy down the right, he'll go there. If he's getting joy in the hole, he'll play there."

The unanswered question for United and their main challengers – lined up like a phalanx in the top four places as of Saturday evening – is what happens when Rooney's light fades again. Cristiano Ronaldo did the job last season, though the swagger and the step-overs have gone at present, and it comes to something when you resort to histrionics against West Bromwich defenders at home. Ronaldo couldn't even summon much joy after sweeping home Rooney's pass for United's second. "He is starting to get the tempo of his game back," Ferguson insisted, but the Portuguese is a curiosity.

Baggies manager Tony Mowbray, just like Ince at Blackburn two weeks ago, pointed out the financial gulf between the sides, and said his team could not compete with that. Though his central defenders Ryan Donk and Jonas Olsson coped stoically for the first half, this was not a game to draw too many conclusions from, though Dimitar Berbatov – who poked out a foot to divert United's third goal, his first in the Premier League – and his manager both judged it to be United's best performance of the season.

The second half – and United's three goals in 16 minutes – certainly bore out that assessment. United have fulfilled in their last two displays their manager's prophecy that October would be the month they crashed on to the scene. What's more, Rooney is another year older this week, too – his 23rd birthday falls on Friday – and he, for one, believes he will prove his manager's prognosis right. "I'd like to think this will be the end of me scoring in bursts," he said. "I've said I'd like to score more consistently and hopefully I can start to do that now. I've worked on every part of my game and thankfully it's starting to pay off."

Goals: Rooney (55) 1-0; Ronaldo (69) 2-0; Berbatov (71) 3-0; Nani (90) 4-0.

Manchester United (4-4-2): Van der Sar; Rafael (Neville, 64), Ferdinand, Vidic, Evra (O'Shea, 35); Ronaldo, Fletcher, Giggs, Park (Nani, 70); Berbatov, Rooney. Substitutes not used: Brown, Evans, Gibson, Kuszczak

West Bromwich Albion (4-5-1): Carson; Zuiverloon, Donk, Olsson, Robinson; Morrison, Koren, (Moore, 72) Valero, Greening, Brunt; Bednar (Miller, 52). Substitutes not used: Kiely, Hoefkens, Cech, Barnett, Macdonald

Referee: M Halsey (Lancashire).

Man of the match: Rooney.

Attendance: 75,451.