Cristiano Ronaldo scored two goals that helped Real Madrid assure its place in the last 16 of the Champions League with a 3-1 win away to Olympique Marseilles.

Real Madrid's Cristiano Ronaldo (L) kicks the ball as Olympique Marseille's Gabriel Heinze (R) looks on during their Champions League soccer match at the Velodrome stadium in Marseille December 8, 2009. [Xinhua/Reuters Photo]

The Portuguese international once again showed his enormous value to his team, which qualified as leader of Group C.

Real Madrid went into the game knowing that only a defeat by 3-0 or more would see them knocked out of the competition.

Coach Manuel Pellegrini decided to leave French striker Karim Benzema on the substitutes' bench, despite Benzema's goal against Almeria at the weekend.

Meanwhile midfielder Rafael Van der Vaart was in the side, playing in a midfield position behind Gonzalo Higuain and Ronaldo. Former Real Madrid defender Gabriel Heinze started the game in the heart of the Olympique defense.

Real took the lead after just five minutes. Ronaldo took a free kick from around 30 yards out and crashed the ball past Mandanda to put his side ahead.

Olympique leveled just five minutes later when Lucho Gonzalez fired a rebound home from inside the Real Madrid area.

The home side then had a goal ruled out when Brandao was adjudged to have strayed offside.

Once again Ronaldo posed the danger to the French goal when he hit the post with a header just before the half hour, prompting a scramble from which neither Sergio Ramos and Higuain was able to push the ball home.

Raul Albiol put Real Madrid back in front with a close range shot following a corner 15 minutes into the second half, but once again the Olympique tried to get level.

They should have done so six minutes later, but Lucho fired a penalty against the crossbar following a foul committed by Iker Casillas.

Ronaldo sealed the win 10 minutes from time firing into an empty net following a pass from Lassana Diarra.

Elsewhere Atletico Madrid secured a place in the Europa League despite a 3-0 home defeat at home to Porto. Atletico ends the group phase with just three points from six games and a goal average of minus nine, but qualifies due to the away goal scored against APOEL Nicosia.