LISBON - Goal-machine Cristiano Ronaldo is at the peak of his career but the world's most expensive player still has one unfulfilled ambition - to win a major international trophy for Portugal.

Portugal's Cristiano Ronaldo gestures during their international friendly soccer match against Turkey at Luz stadium in Lisbon June 2, 2012. [Photo/Agencies]

The 27-year-old Real Madrid forward's trickery, pace and ferocious shots will be a highlight for soccer lovers at Euro 2012 where he hopes to captain his country to a long-awaited success.

Like his nemesis, Argentine Lionel Messi of Barcelona, Ronaldo has chronically underperformed at international tournament finals.

His determination to do well will be stronger than ever after Real Madrid's semi-final exit in the Champions League this season despite their title success in La Liga.

At Euro 2004, when Portugal still relied on the declining powers of Luis Figo and Rui Costa, Ronaldo came agonisingly close to glory but Greece shocked the hosts in the final.

A young Ronaldo was left in tears and, though he was picked for the team of the tournament, he scored only twice. If that was a personal disappointment, it was deepened in the three major tournaments that followed when he scored just once at Euro 2008 and at the World Cup finals in Germany and South Africa.

His critics say this is the main reason that Ronaldo, like Messi, cannot be compared to past greats like Pele, Diego Maradona or Eusebio, all of whom are remembered for stunning tournament performances.

"Cristiano has always had a lot of responsibility since he was 18," Madrid and Portugal team mate Pepe has said.

"People put a lot of pressure on him. The squad needs to give support to Cristiano so Cristiano can be calm and play his football."

Ronaldo's club record with Manchester United and Real Madrid speaks for itself.

Last year he added Spain's Copa del Rey to his Premier League, Champions League and FA Cup titles at United. This year he added La Liga to that list as Madrid fended off Barcelona.

He won the FIFA World Player of the Year award in 2008 and two European Golden Boot trophies, including in the 2010/2011 season when he grabbed 40 league goals, a figure surpassed this term with 46.   

Goal machine

His success is as much a product of his own hard work as his talent as he has improved himself, and his goal ratio, steadily.

He is close to averaging a goal in each game during the last two and a half seasons at Real Madrid compared to 0.5 goals per game in six seasons at United where he developed from a winger into an all-round striker.

For Portugal coach Paulo Bento one key task will be to bring out the best in Ronaldo, enabling him to repeat his club form.

Since succeeding Carlos Queiroz in September, 2010, he appears to have found the right approach to this challenge, Ronaldo's form for Portugal having improved along with his integration into the team.

Ronaldo was Portugal's top scorer in the qualifiers and it was one of his trademark tomahawk free kicks that inspired a memorable 6-2 aggregate victory over Bosnia to secure their passage to the finals.

His combination of speed and stepovers may be thrilling, but it will be his part in Portugal's collective effort that matters as they bid for success.