After years of under delivering on his vast potential, David Nalbandian is ready to live up to his promise.

We're in Villa del Dique, a small town of around 2,800 people in Cordoba, Argentina. David Nalbandian has interrupted his three-week holiday to attend an unusual press conference: He has been invited by Luis Santos, his first tennis coach, to deliver a speech to 100 children, revealing his secrets of how to beat both Roger Federer and Rafael Nadal.

A jovial Nalbandian also relates how he came to be a tennis player. The tale is one of an undecided boy who played soccer when tennis bored him, who enjoyed watching rally car competitions in his hometown, but who later learned that he could make a career by wielding a racquet. "When I was 11, I would switch between tennis and other sports," Nalbandian recalls. "Three years later, I would be playing for four hours against older people. I was a total tennis fan. Today, I just practise for an hour and a half, but focusing on what I need to improve. Those are different stages in your career."

Suddenly, a girl stands up and raises her voice to ask a crucial question: "Next year, are you going to be focused only on tennis?" Grinning, Nalbandian promptly answers: "Yes, as always." The room erupts with laughter.

As someone who until recently had relatively little to show for his prodigious talent, the response was like a bittersweet joke. Despite finishing no lower than No. 12 for five consecutive years between 2002-06, the Argentine had won just five ATP titles, with his 2005 Tennis Masters Cup final triumph over an injured Roger Federer his only victory at Masters Series or Grand Slam level. He reached the Wimbledon final in 2002 and a year later held match point against eventual champion Andy Roddick in the US Open semifinals, but his game that promised so much had delivered so little in terms of hard results.

That is why 2007 was shaping as such a bitter season for Nalbandian, who at 25, should have been hitting his peak. In mid October, with just three weeks to play before his miserable season was over, Nalbandian came into ATP Masters Series Madrid at No. 25 in the South African Airways ATP Rankings after reaching just one quarterfinal (Barcelona) all year.

But in one of the most dramatic performances in recent memory, Nalbandian became the first player to defeat World No. 1 Roger Federer and World No. 2 Rafael Nadal in the same tournament on two occasions en route to winning back-to-back ATP Masters Series titles in Madrid and Paris and finishing the year inside the Top 10 (at No. 9) for the fifth straight year. To the relief of all eight competitors at Tennis Masters Cup, Nalbandian missed a place in Shanghai by one spot. "I don't know what the hell he's been doing all the other tournaments," Federer quipped.

So which David Nalbandian will show up in 2008: the one who over promises, or the one who over delivers? Certainly the goals are lofty, starting with a quest to break the Grand Slam domination of Federer and Nadal, who have shared the past 11 majors since Marat Safin won the 2005 Australian Open after saving match point against Federer in the semifinals.

"My first Grand Slam, an Olympic medal in Beijing and the Davis Cup," Nalbandian says of his ambitious hit-list for 2008. "Each one represents a different satisfaction - the first one, rather individual; the others would mean to leave my mark on the sport's history in Argentina.

Nalbandian, who turned 26 on January 1, is more tentative assessing his chances to become No.1, but still brings the subject to the table. "I'll go for it, no doubt. Of course, it's extremely difficult. What Federer does is out of this world, winning almost every tournament he plays. But at least I will say I'm going to try."

Spaniard Alex Corretja, another former Tennis Masters Cup champion, certainly sees further improvement for Nalbandian in 2008. "The creativity Nalbandian shows on court is astonishing. Next year, he should at least be in the Top 5." [Nalbandian has never finished in the year-end Top 5. Indeed, he has finished higher than No. 8 just once - in 2005 when he ended at No. 6.]