With 100 percent of precincts reporting, Beshear had a lead of 5,333 votes out of more than 1.4 million counted, or a margin of 0.3 percentage points. Beshear received 709,673 votes, Bevin received 704,523 votes, and Libertarian candidate John Hicks got 28,414 for 2 percent of the vote.
The bitter rivals gave competing speeches in which Beshear claimed victory while Bevin refused to concede.
"My expectation is that he (Bevin) will honor the election that was held tonight," Beshear said. "That he will help us make this transition. And I'll tell you what, we will be ready for that first day in office, and I look forward to it."
Bevin called it a "close, close race" and said he wasn't conceding "by any stretch."
"We want the process to be followed, and there is a process," he said.
Bevin hinted that there might be "irregularities" to look into but didn't offer specifics.
There is no mandatory recount law in Kentucky. Bevin may request counties recanvass their results, which is not a recount, but rather a check of the vote count to ensure the results were added correctly. Bevin would need to seek and win a court's approval for a recount.
Beshear dominated in the state's urban areas in Louisville and Lexington and won some traditionally Republican suburban counties in the state's northernmost tip, just south of Cincinnati, to offset Bevin's strength in rural areas. Beshear won just 23 counties, while Bevin carried 97.