Republican presidential challenger Mitt Romney scored an important psychological victory over President Barack Obama in their first debate, putting the incumbent on the defensive over the weak economy and high unemployment rate.

A listless Mr Obama failed to counter-attack effectively on most occasions. More surprisingly, he did not capitalise on Mr Romney's recent vulnerabilities, such as the secretly-taped remarks of him disparaging 47 per cent of voters as "victims'' who depend excessively on the government.

Snap polls by several media organisations such as CNN and CBS pointed to a clear and convincing win for Mr Romney following the 90-minute debate in Denver, Colorado. The two candidates will meet for two more debates later this month, while their running mates will face-off in a similar fashion next Friday.

While he gave no new policy details and independent fact-checkers faulted him for repeating false claims on healthcare and tax policies, Mr Romney generally gave crisper answers and frequently connected his responses to the plight of ordinary Americans struggling to make ends meet.
 
On the question of how he would create new jobs, Mr Romney began by recounting the plight of a woman in Denver who approached his wife Ann for help after she had to give up the family home and her husband lost four part-time jobs in three years.

"The answer is, yes, we can help, but it's going to take a different path, not the one we've been on," said Mr Romney before launching into a short summary of his five-point plan to revive the economy.

This involved greater energy independence, opening up more trade with Latin America, upgrading workers' skills and education, balancing the budget, and promoting small businesses.

One of the President's more effective jabs came towards the end of the debate, when he criticised Mr Romney for being unwilling to "say no to some of the more extreme parts of his party''. But that was largely lost in Mr Obama's frequent forays into detailed and tedious explanations of his own administration's record on healthcare and financial reforms.