Real Madrid forward Cristiano Ronaldo has suggested that the toughest challenge of his career came in the Premier League.
Ronaldo has enjoyed a glittering period with Real, with 450 goals being scored in 437 appearances and two La Liga titles and three Champions League crowns being won during the star's spell at the Bernabeu.
However, in an interview with Spanish television show El Chiringuito, Ronaldo revealed that he regarded his battles with left-back Ashley Cole as his biggest challenge.
Between 2003 and 2009, Ronaldo spent six years with Manchester United where he went head-to-head with Cole, who represented both Arsenal and Chelsea.
The pair also faced each other on the international scene with Portugal and England respectively.
