According to CNN:
A CNN/USA Today/Gallup snap poll taken immediately after the presidential debate Friday night found that respondents gave a slight, statistically insignificant edge to Sen. John Kerry over President Bush, 47 percent to 45 percent.
The respondents included 515 registered voters who watched the debate. Their political affiliations broke down as 38 percent Republican, 32 percent Democratic and 30 percent independent.
With this kind of oversample of Republicans, then Kerry must have thrashed Bush among the poll's independents.
I just checked the polls internals at the Gallup website: