Colorado Democratic Governor John Hickenlooper declared victory on Wednesday in a tight re-election race over his Republican challenger, former U.S. Representative Bob Beauprez.
Beauprez refused to concede on the grounds that some 120,000 votes still had to be counted, the Denver Post reported.
Returns posted on the Colorado secretary of state website showed Hickenlooper with 48.35 percent of the vote, compared to 47.12 percent for Beauprez, with 53 of 64 counties reporting. Local media projected Hickenlooper the winner shortly before he declared victory.
"I think I can demonstrate that one with no sleep can still experience great joy," Hickenlooper said in remarks at the state Capitol in Denver.
The declaration came the morning after Colorado voters ousted first-term Democratic Senator Mark Udall in favor of Republican Representative Cory Gardner in a race that was a big win for Republicans in the swing state.
(Reporting by Cynthia Johnston and Steve Gorman; Editing by Dina Kyriakidou)