Many questioned whether Cristiano Ronaldo was worth the hassle he seemed determined to cause Manchester United last summer.
Apparently desperate to join Real Madrid at all costs, Ronaldo's days as a Premier League player seemed numbered for much of last summer as all the familiar tactics of press leaks and un-named sources suggested he would start this campaign as the new jewel in La Liga's crown.
Some portrayed United boss Alex Ferguson as a desperate old man, as he tried to hang onto his favoured son even though it was clear he was determined to fly the nest, but this memorable spring night in North London showed just why Ferguson's belligerence was worthwhile.
United will be in Rome to defend their Champions League crown later this month due primarily to the right boot of a player whose wonder-goal sealed their passage to this semi-final tie with the winner in Porto and a performance at the Emirates Stadium that left you wondering why anyone ever doubted his talents.
After setting up the seventh minute opening goal for Ji-Sung Park, thanks in no small part to a slip by Arsenal youngster Kieran Gibbs, his own moment of iconic Champions League glory confirmed his season of occasional slumber could yet end in the grandest manner.
Most of us packed into the overflowing press seats at Emirates Stadium believed Ronaldo was showing arrogant ambition as he lined up a free-kick that was all of 40 yards from goal eleven minutes into this tie. With many of United's big guns up from the back, it seemed as if floating the ball into the box in a bid to expose Arsenal's age-old flaws in defending set plays was a better plan.
Ronaldo's had different ideas. While Arsenal keeper Manuel Almunia should never have been beaten from such a lengthy and speculative shot, the pace, the power and movement Ronaldo managed to impart on his set-play was majestic.
Arsenal fans groaned at the moment that ensured their fourth season in succession would end without a trophy, but as the ball crashed into the Arsenal net and Ronaldo ran half the length of the field to celebrate, his return to the pinnacle of the world game was complete.
Manchester United's No.7 must have felt a degree of wounded pride after a season that has seen Barcelona's Lionel Messi take over as the pound for pound world champ, yet longevity of brilliance is the mark of a true great and this single, venomous strike ensures Ronaldo's campaign will still be remembered with fondness.
He may well end this season as the Premier League's leading goal scorer and with another domestic championship piece of gold in his back pocket. Oh and he may even get his wish of having Champions League Final showdown with the very man who has stolen his thunder as Leo Messi and Barcelona may well lie in wait for United in Rome.
You had to feel a degree of sympathy for the Arsenal fans after this comprehensive drubbing on a night when they banished the notion that the Emirates Stadium is the home of all that is ugly in the modern game. Corporate hospitality is required to fund the club's sparkling stadium, yet the men in suits whose interest is more in their free champagne than the football doesn't always create the sort of atmosphere you would hope for at a major club.
However, this was a night when the Emirates came alive for one of the first times. The rapturous welcome that greeted the two teams onto the pitch prior to a rendition of that always uplifting Champions League anthem suggested Arsenal could be swept on a wave of emotion all the way to the Final in Rome.
Indeed, they started in a manner that suggested their silky passing football could unnerve a United side that looked a little rattled as they chased the ball in vain for the first five minutes. Arsenal only have one game plan, but it can beat the best of opponents when executed with precision.
Early promise soon turned to a grizzly reality as their old defensive problems in dealing with set-plays surfaced again. In addition, once United's five-man midfield unit managed to snatch the ball from Arsenal's grasp, their powerful presence was a quality Wenger's kids could not overcome.
A little like their demise in the FA Cup semi-final against Chelsea last month, an experienced and weighty opponent had too much for Arsenal and United boss Ferguson should take credit for selecting what proved to be a perfectly balanced side for this occasion.
Arsenal's misery was completed as United broke with pace and power with an hour gone and after Park and Rooney ripped through the broken Gunners, Ronaldo was on hand to apply the finishing touch. This one-sided Champions League semi-final was officially over.
It was a cue for Arsenal fans to flow out of the Emirates Stadium in their masses, grumbling at Wenger's tactics and philosophies as they came to terms with the reality that another season of false promise was complete. The comprehensive nature of their trashing in this tie may have ramifications for the future of some key Arsenal players, but such debates are for another day.
"It's too soon for me to think about whether this team are good enough to bring success to this club," admitted a visibly shaken Arsene Wenger. "We have been on a good run in the league, but in the two big cup games we have played recently, we haven't been good enough.
"This is the most disappointing night of my Arsenal career as it feels as if we let everyone down. The fans were up for it, but this game was over before it started for us. It hurts so much."
Wenger's understandable despair was contrasted by Ferguson's glee and his praise of match winner Ronaldo was complete. "Arsenal started so aggressively, the ball was zipping around and the crowd were right behind them, but they couldn't handle Ronaldo once we got the ball to him," he said. "Ronaldo was the difference between the sides and when you see him performing like that, he is fantastic player.
"I have some sympathy for Arsene Wenger because I think you can still be a great manager even if you don't win the Champions L eague, but that is not the way it will be portrayed in the media."
Ronaldo has been accused of being a cheat, a player who doesn't perform in the big games and an egomaniac who is in this game for himself rather than the good of his team.
Even if all of those flaws are true, Cristiano Ronaldo is worth his weight in gold.
MAN OF THE MATCH: Cristiano Ronaldo
Special players confirm their class on nights like this and Ronaldo stole the show as only he can.
SYMPATHY FOR GIBBS: It was hard not to feel sorry for Arsenal youngster Kieran Gibbs as his slip gave Park the chance to open the scoring. Wenger took him off at half-time to protect him from a night that could have tarnished him for good.
FERGIE BANTER: When asked who he wanted to play in the Final, the United boss has a novel answer. "Barcelona or Chelsea will be tough so I'll say neither of them. I think we should have a bye and they should give us the trophy now."
ARSENAL VERDICT: On a night when Wenger's young team needed to show they had become men, they failed their exam in desperate fashion. Where they go from here is open to debate.
UNITED VERDICT: Their unexpected dip a few weeks ago is banished to the history books. Form is temporary, yet United's class has proved to be permanent.