Democrat Barack Obama holds a five-point lead over Republican John McCain, with little immediate indication their final public debate did much to sway the U.S. presidential race, a Reuters/C-SPAN/ZOGBY poll showed on Friday.

Obama''s edge over McCain held steady at 49 percent to 44 percent among likely U.S. voters in the four-day tracking poll, unchanged from results before the two men met on Wednesday for their third and last debate before the November 4 election.

The poll of 1,210 likely voters had a margin of error of 2.9 percentage points.

Pollster John Zogby said Friday''s results -- in which the most recent day''s results are added and the oldest day''s results are dropped in an effort to measure changing momentum -- may not reflect the full impact of the debate.

"Only one-quarter of this sample is post-debate, so we''ll have to wait a few more days to see," he said. "We''ll have to look tomorrow to see if there was any McCain boost at all."

Quick polls taken after Wednesday''s debate judged Obama the victor, joining a string of surveys that show him ahead both in national polls and in most of the battleground states where the presidential election will be decided.