Voters say President Barack Obama did a better job than Republican challenger Mitt Romney in Monday's debate but their opinions of each candidate did not shift significantly, according to a Reuters/Ipsos poll released on Tuesday.

Some 47 percent of registered voters surveyed in the online poll judged Obama the victor, while 31 percent believed Romney won.

But neither candidate's favorability ratings shifted in the wake of Monday's debate, the last of three televised matchups before the November 6 election. Likewise, voter assessments of the candidates on a range of issues from the economy to foreign policy did not change by a statistically significant margin.

Obama's favorability rating ticked up by 1 percentage point to 57 percent, a statistically insignificant change. Romney's favorability also inched up 1 point, to 54 percent.

The full impact of the debate on the race won't show up in opinion polls for several more days, but it is unlikely that it will give either candidate a big enough boost to break their statistical tie, Ipsos pollster Julia Clark said.

"By this point in the election cycle a lot of people have formed a more complete view of each candidate," Clark said.

The accuracy of Reuters/Ipsos online polls are measured using a credibility interval. The survey of 515 registered voters, conducted on Tuesday following the debate, has a credibility interval of 4.9 percentage points.

The debate did appear to move the needle with some voters, but not in a way that clearly benefited either candidate.

Some 22 percent of those surveyed said they had a more positive view of Obama after the debate, while 19 percent said they had a more negative view, and 54 percent said their opinion did not change one way or another.

The same pattern held for Romney: 22 percent viewed him in a more positive light, 21 percent viewed him more negatively and 48 percent said their opinion did not change.

A separate Reuters/Ipsos daily tracking poll has shown Obama and Romney to be within 3 percentage points of each other since the first debate on October 3. As of Tuesday, Obama led by 1 percentage point, well within the poll's credibility interval.