The United number 7's haul of 19 goals in 20 league games is unmatched in England, Italy, France, Spain or Germany. In Italy, the in-form striker is David Trezeguet of Juventus with 15 goals in Serie A, while Karim Benzema of Lyon - United's next Champions League opponents - is top scorer in France's Ligue 1, also with 15 goals.
Luis Fabiano of Seville and Real Zaragoza's Diego Milito are both in the running for Spain's Pichichi trophy, awarded to La Liga's top goalscorer, both with 14 goals.
In Germany's Bundesliga, four players are locked on nine goals - Bayern Munich's Luca Toni and Miroslav Klose, Diego of Werder Bremen and Rafael van der Vaart of Hamburg.
Ronaldo's main challenger for the European Golden Boot is Ajax's Klaas-Jan Huntelaar, top scorer in Holland with 20 goals. However, it's Ronaldo's goal haul that has got everyone talking across the continent. No wonder Sir Alex is convinced the Portuguese winger is about to rewrite the record books.
"His goals invite comparison with George Best who became United's highest-scoring winger when he hit 32 goals in the 1967/68 season on his way to being voted European Footballer of the Year," commented the United boss in his Portsmouth programme notes.
"Considering he is scoring at the rate of almost a goal a game, I certainly won't be betting against him joining Best in the record books!"
Now with 27 goals in all competitions, neither will anyone else.