Former Democratic Rep. Ann Kirkpatrick has defeated former Republican state lawmaker Jonathan Paton to win Arizona's 1st Congressional District seat.
Kirkpatrick had enough of a lead Wednesday for The Associated Press to declare her the winner.
The race had been considered a tossup and featured millions of dollars in ad spending.
Paton counted on backing from conservatives and moderates wary of Kirkpatrick for backing President Barack Obama's polices when she represented the district from 2008 until 2010.
The state's largest district runs from Flagstaff through eastern Arizona counties and then west into parts of Pinal County and includes the Navajo Nation where Kirkpatrick has strong support.
The district has more Democrats than Republicans but nearly a third of registered voters are independents.