Holders Manchester United [ Images ] gave Arsenal [ Images ] a masterclass in what is required to be European champions by beating them 3-1 to seal a 4-1 aggregate victory in their Champions League [ Images ] semi-final on Tuesday.
It extended United's record unbeaten run in the competition to 25 games and inflicted Arsenal's first defeat in Europe at their new Emirates home.
United have fared badly at Arsenal in recent years, winning just one of their last 10 visits, and there was a real mood of optimism among the home fans in the opening exchanges as the visitors looked tentative.
However, within 11 minutes the tie was effectively over.
Arsenal manager Wenger [ Images ] said in his programme notes that he had been plotting for the return leg non-stop in his head since the 1-0 defeat at Old Trafford last Wednesday.
But all the Frenchman's meticulous plans went up in smoke after eight minutes as young left back Kieran Gibbs [ Images ] endured the worst moment of his fledgling career.
There seemed minimal danger as Ronaldo scurried to the by line and cut back a low cross but the 19-year-old Gibbs lost his footing and despite his desperate attempts to recover his balance, the lurking South Korean Park lifted a shot past Almunia [ Images ].
Ronaldo was booed loudest by the home fans when the teams were announced but the Portuguese replied with a mesmerising display of footwork and power.
Three minutes after Park's opener, the European and World Player of the Year was fouled by Robin van Persie [ Images ] way out on the right.
It seemed an improbable distance from goal but he only had one thought in his mind as he ran up and sent a ferocious free kick dipping inside Almunia's near post from 40 metres.
Wayne Rooney [ Images ] then almost made it 3-0 with a right-foot curler that Almunia tipped round the post.
The lop-sided nature of the contest continued after the break as an air of resignation hung over north London [ Images ].
Ronaldo revelled in the wide open spaces down Arsenal's flanks and was close to a second when he cut in past Gibbs's halftime replacement Emmanuel Eboue [ Images ] and lashed in a shot that Almunia smothered around the post.
There was no respite for Arsenal as with just under half an hour remaining United carved out a goal on the counter-attack of extraordinary quality.
Park and Ronaldo played a one two before Park sent Rooney marauding deep into Arsenal territory to slide a pass across the area for Ronaldo to clip a shot past Almunia.
It was the signal for thousands of Arsenal fans to leave and for United manager Alex Ferguson [ Images ] to ring the changes with Rooney, Anderson and Patrice Evra [ Images ] all coming off in readiness for the weekend league match against Manchester City [ Images ].
What would have been a perfect night for United was marred after 75 minutes when Fletcher tangled with Cesc Fabregas [ Images ] in the area.
The penalty that Van Persie thumped past Edwin van der Sar [ Images ] looked ample punishment but Fletcher was shown a red card by referee Roberto Rosetti.