The step-over kid finally arrives on the big stage

Apparently, Manchester United have had a poor season and, apparently, this is largely due to the fact that Sir Alex Ferguson has failed to replace David Beckham adequately. Cristiano Ronaldo, the outstanding performer in United's FA Cup-winning team yesterday, might have something to say about that.

Sven Goran Eriksson presented the man-of-the-match award to Ruud van Nistelrooy, but few wearing red at the Millennium Stadium agreed with the decision. "There's only one Ronaldo," came the chant in support of the United right-winger immediately after the decision was announced over the tannoy. Golden Boots is fast erasing the memory of Golden Balls.

Right from the off yesterday it was clear that Ronaldo was in the mood to make his mark. With just eight minutes gone, the Portuguese teenager produced an outrageous piece of individual skill, crossing the ball with a scissors move of exceptional quality. What a pity Paul Scholes delivered an air shot rather than the finish the set-up deserved.

Ronaldo was at it again nine minutes later, flicking the ball around Peter Sweeney before embarking on a mazy run towards goal. Or was it a dance? So good is his close ball control that one sometimes struggles to follow his exact moves. The same could be said of the Millwall players, who had to resort to strong-arm tactics to stop him. On this particular occasion, it was a David Livermore and Dennis Wise sandwich that brought the exhibition to a halt.

And he is demanding of himself, too. When his 30th-minute shot found the side netting, he looked dejected. No matter that even Van Nistelrooy would have struggled to do any better from such an acute angle, Ronaldo could not hide his displeasure. This is clearly a player built in his manager's mould, someone who will settle for nothing less than perfection.

At least he cannot blame himself for failing to score in the 41st minute. Having latched on to a clever Van Nistelrooy flick, Ronaldo skipped away from Marvin Elliott with an excellent first touch and somehow found space for a right-foot shot. Only the reflexes of the Millwall goalkeeper, Andy Marshall, prevented the United winger from scoring the opening goal.

He would not be denied that honour, though, as his headed goal three minutes later confirmed. So much for the criticism that Ronaldo is reluctant to get stuck in. The run and leap, not to mention the powerful header, would have made Alan Shearer proud.

What is perhaps most frightening about Ronaldo is his age. "He is still only 19 and will just get better with time," Ferguson said. "He will be a very special player." In fact, he was maturing before our very eyes yesterday. His second-half performance was not just quieter, but also more measured. With the lead secured there was no need to take risks.

This is not to say that Ronaldo suddenly stopped performing. There were the obligatory step-overs and drag-backs, but no unnecessary show-boating. Only once Van Nistelrooy had netted United's second did their No 7 resume his artistry. Such was his impact on the increasingly jittery Millwall defence that his mere presence was enough to force individual errors towards the end of the match.

Relief for Millwall only came six minutes from time when Ronaldo was substituted. But, by then, the damage had been done. Ferguson's critics should now ask themselves the question: would Beckham have made a bigger impact than his ever-improving replacement?