United's opponent was FC Barcelona, who already clinched a double of La Liga and the Copa del Rey in Spain. That Barcelona side utilized the Tiki-tata style to perfection with an incredible pool of gifted players, including a then-21-year-old Lionel Messi, who at the time was considered by some to be the best player in the world.
Not to be outdone, United were the most dominant side in England. Ronaldo was a key component of a side that won their third straight Premier League title. Despite a season that was delayed due to ankle surgery, Ronaldo still scored 26 goals in all competitions.
On this Roman night, everything changed. Barcelona overwhelmed Man United in every imaginable facet. Their 2-0 win was affirmed by a brilliant headed goal from Messi, punctuating his brilliant season and cemented the claim that he was the world's best.
Fast forward three years and Ronaldo finds himself in a different situation.
Ronaldo has rose to new heights with Real Madrid by categorically dominating La Liga with a record-breaking 42 goals. Ronaldo's heroics have Madrid on the verge of their first league title since 2008, the same year he was named the best player in the world.
Ronaldo continued his great play into the Champions League, scoring ten goals or 29 percent of the goals that Los Blancos have in the tournament.
After falling to Barca in the semifinals last year, Ronaldo put together a strong two-goal performance in the first half of the second leg in this year's semifinal to put Madrid on the brink of a finals appearance.
However, Bayern Munich were able to equalize the aggregate score on a Arjen Robben goal and the match subsequently went to spot kicks.
Bayern were up 1-0 on penalties when Ronaldo went up to take Madrid's first spot kick. While walking to take the penalty, you could see a swagger and determination in his steps toward Manuel Neuer.
This spot kick was an opportunity for Ronaldo to make up for his miss in the 2008 Champions League final with Man United that nearly gave Chelsea the title. Everyone watching the match remembered that moment and they also knew that the image of the miss in Moscow would be forever blurred with a goal here.
But something went wrong on his run-up; that confidence from just seconds before melted away. Ronaldo slowed down before shooting the ball to Neuer's right, which was saved by German keeper.
This was a completely different penalty than the one that Ronaldo took earlier in the match. On that prior penalty, Ronaldo approached the ball slowly, but showed more aggressiveness and slotted the ball to Neuer's left for the first goal of the match.
Madrid went on to lose on penalties 3-1, though this failure to advance was by no means completely Ronaldo's fault.
This failure to reach the final will not harm Madrid as it did the year before (partially because Barcelona had already been eliminated in a far more humiliating manner to Chelsea) but Ronaldo now finds himself with the opportunity of having his best year since 2008.
Ronaldo will still have a chance to beat Messi in his total amount of goals scored in La Liga, but Ronaldo will also get to shine in the European championships, where that shadow of Messi vanishes this summer.
Unlike in Euro 2004 or Euro 2008, Portugal have the odds against them when it comes to winning the tournament, due in large part to the strong ability that the likes of Spain, Germany and the Netherlands possess.
Due in large part to their placement in the group of death, Portugal are expected to fail while both the Germans and the Dutch are expected to advance.
Even the fourth side in the group, Denmark, has achieved success against Portugal in qualification for both the 2010 World Cup and Euro 2012.
Portugal are not given any help from some disappointing performances in international tournaments since Ronaldo joined the senior ranks. After failing to win Euro 2004 on their home turf, Portugal fell out early in both Euro 2008 to the Germans and in the 2010 World Cup to Spain.
Though both Germany and Spain are obviously among the top sides in the world and are expected to defeat Portugal, Ronaldo was noticeably absent from both tournaments. Ronaldo ended up tallying a goal in the group stage of both tournaments, with both sides that Ronaldo did score against ended up not reaching the knockout stage.
In the lead up to the tournament, Ronaldo will be the biggest star showcased and will be expected to show brilliance at any given time.
That brilliance was worthy of the record £80 million transfer between Madrid and Man United in June 2009 and the action of the Madrid fans to pack the Bernabeu to watch the ceremony commemorating the arrival of their new Galactico that July.
The chance that Ronaldo will have is one that could give him the FIFA World Player of the Year award and at the very least, a new debate among football fans over whom is the better footballer, Ronaldo or Messi.
If Ronaldo can capitalize on this opportunity, his career will shift a complete 180 degrees and so will his legacy. At the very least, he won't be remembered as the second-best player of his era anymore.