Republican Matt Salmon conceded the governor's race Sunday night to Democrat Janet Napolitano as officials finished counting tens of thousands of outstanding ballots.

Napolitano, Arizona's attorney general, led by 11,423 votes with only about 12,000 ballots left to be counted. The Associated Press called the governor's race for Napolitano on Wednesday after results from Maricopa County showed Salmon would be unable to come back.

"The fact is I think Arizona is a better place for the strong debate that has taken place,'' said Salmon, a former congressman.

Salmon had held out hope that the more than 200,000 early ballots and ballots needing verification left to count after Tuesday would bring him back.

Napolitano scheduled a news conference for later Sunday night.

"I am both elated and humbled to be chosen as Arizona's next governor,'' Napolitano said in a statement. "I am grateful to the voters of Arizona for sticking through a long campaign season and I want to thank my supporters for their part in making history.''

Napolitano will succeed the term-limited Gov. Jane Hull in January.

Salmon gained steadily after election night as Maricopa County counted about 180,000 outstanding ballots and other counties finished with their ballots. But his boost in Maricopa County wasn't nearly enough to come back from a deficit of 25,000 votes after election night.

As of Sunday night, Napolitano had 560,653 votes, or 46.2 percent. Salmon had 549,230 votes, or 45.2 percent.