WASHINGTON (Reuters) - President Barack Obama's lead over Republican challenger Mitt Romney has narrowed to just 2 percentage points since Romney's strong performance in their first debate, according to a Reuters/Ipsos poll released on Friday.

In more bad news for Obama, one in five voters said the Democrat's performance in the contest in Denver on Wednesday made them feel more negative about him, while almost a third said they felt more positive about Romney.

The online poll conducted from Monday to Friday showed 46 percent of likely voters backed Obama, versus 44 percent for Romney. Obama had led by 48 to 43 percent in Thursday's daily tracking poll, the first to include a day of interviews after the debate.

(Editing by Christopher Wilson)