Democratic presidential candidate, Senator Barack Obama, D-Ill., left, and Republican presidential candidate, Senator John McCain, R-Ariz., address a question during the presidential debate Sept. 26 at the University of Mississippi in Oxford, Miss. Moderator Jim Lehrer of PBS is at the center. Photo: AP Wide World Photos

WASHINGTON - A pair of one-night polls gave Barack Obama a clear edge over John McCain in their first presidential debate.

Fifty-one percent said Mr. Obama, the Democrat, did a better job in the Sept. 26 faceoff while 38 percent preferred the Republican McCain, according to a CNN-Opinion Research Corp. survey of adults.

In other national polls, Mr. Obama also fared well. By Sept. 29, the Gallup Daily poll had Mr. Obama winning 50-42 percent over Sen. McCain and the Rasmussen Daily poll had Mr. Obama at 50-44. A Sept. 28 USA Today/Gallup poll out had Mr. Obama winning the debate by a 48-34 percent margin. Sen. McCain had a one-point lead over Mr. Obama according to polls in battleground states.

Mr. Obama was widely considered more intelligent, likable and in touch with peoples’ problems, and by modest margins was seen as the stronger leader and more sincere in the CNN poll. Most said it was Mr. McCain who spent more time attacking his opponent.

About six in 10 said each did a better job than expected. Seven in 10 said each seemed capable of being president.

In a CBS News poll of people not committed to a candidate, 39 percent said Mr. Obama won the debate, 24 percent said Mr. McCain and 37 percent called it a tie. Twice as many said Mr. Obama understands their needs than said so about Mr. McCain.

Seventy-eight percent said Mr. McCain is prepared to be president, about the same proportion of uncommitted voters as said so before the debate. Sixty percent said Mr. Obama is ready—a lower score than Mr. McCain, but a solid 16-percentage-point improvement from before the debate.

In another Obama advantage in the CBS poll, far more said their image of him had improved as a result of the debate than said it had worsened. More also said their view of Mr. McCain had gotten better rather than worse, but by a modest margin.

The CNN poll involved telephone interviews with 524 adults who watched the debate and had a margin of error of plus or minus 4.5 percentage points. The CBS survey involved online interviews with 483 uncommitted voters who saw the debate and had an error margin of plus or minus 4 points. It was conducted by Knowledge Networks, which initially selected the respondents by telephone. Both polls were conducted the evening of Sept. 26.