Atletico Madrid's defence is one of the best in Europe, but in the first leg it was no match for Cristiano Ronaldo, who has the most Champions League goals in history with 103.

The Real Madrid No.7 is in incredible form, scoring a hat-trick against Atletico and Bayern Munich on Europe's biggest stage.

With one more goal Ronaldo would equal Lionel Messi as six-time Champions League leading goalscorer for the season, which is a tournament record.

It is little surprise that stopping the Portuguese star is the first order of business if Diego Simeone's side are to mount an improbable comeback, and he is the player on all Rojiblanco supporter's minds.

Cardiff is where Real could win the Duodecima and Ronaldo his fourth Champions League, third with Los Blancos.

Zinedine Zidane's totation policy and fitness coach Antonio Pintus' fitness plan means the player is reaching his physical peak at the perfect point of the season.

It is an extreme conversion rate for Ronaldo, whose eight goals have come via just 12 shots these past three Champions League games.

The last time he visited the Estadio Vicente Calderon, the hosts were frustrated by his LaLiga hat-trick- with 21 goals against the Colchoneros, it is little wonder he is the player they fear the most.