Democrat Heidi HeitkampMary (Heidi) Kathryn HeitkampWells Fargo chief defends bank's progress in tense Senate hearing Dems plan to make gun control an issue in Nevada Red-state Dems need more from Trump before tax embrace MORE has won the race for North Dakota Senate, besting GOP Rep. Rick Berg in one of this cycle's most surprising Senate upsets.

Her win keeps retiring Sen. Kent Conrad's (D-N.D.) seat in Democratic hands and gives Democrats further bragging rights in an election cycle that saw them pick up three Senate seats and win several tough toss-up races.

Early Wednesday morning, with 100 percent of precincts reporting, Heitkamp had 160,752 votes, or 50.5 percent of the vote, to Berg's 157,758 votes, or 49.5 percent of the vote, according to the Associate Press.

The outcome of the race remained uncertain until Wednesday afternoon, when multiple North Dakota news sources reported Berg conceded to Heitkamp. Heitkamp's campaign confirmed to The Hill he conceded.

Berg had initially declined to do so, with his campaign issuing a release Tuesday night saying the lawmaker would wait until the state's official vote canvassing process finished on Tuesday of next week to concede the race.

The race was one of the tightest in the nation, and sparse independent polling made it a difficult one to predict.

Berg led Heitkamp in nearly every poll of the race since the primary, though she narrowed the race to a statistical tie in the last survey, in late October.

North Dakota's economy is much stronger than the nation's overall, so this race focused on local and personal issues rather than the job creation and tax reform that occupied many of this cycle's other Senate races.

The red lean of the state — it went for Mitt Romney on Tuesday night — seemed to favor Berg from the outset. He worked to tie Heitkamp to President Obama, and Republicans targeted her for donations from what they called anti-fracking and anti-defense organizations in an attempt to paint her as a hypocrite.

Heitkamp, however, ran a strong campaign, touting her support for Republican pet projects like the Keystone XL Pipeline and coal and natural gas drilling. She also launched attacks blaming Berg for congressional inaction on the farm bill, legislation central to a wide swath of North Dakota voters, a state where agriculture makes up a large portion of the economy.

Democrats also worked to dismantle one of Berg's main advantages: his business experience. They attempted to tie him to a well-known North Dakota real-estate company that mismanaged properties.