Nevada Republican Dean Heller will hold on to his U.S. Senate seat after narrowly defeating Democrat Shelley Berkley.

Berkley conceded the race early Wednesday as results continued coming in showing Heller would be the victor.

Heller was in his third term in Congress representing northern Nevada when Republican Gov. Brian Sandoval picked him last year to replace U.S. Sen. John Ensign, who resigned after a scandal.

Berkley is a seven-term Nevada congresswoman from Las Vegas. She had backing from Democratic Senate Majority Leader Harry Reid and President Barack Obama.

Heller, Berkley and campaign super PACs spent tens of millions of dollars bombarding voters with ads in a vicious race.

Berkley cast Heller as a supporter of big business and oil companies, and no friend of the middle class.

Heller said Berkley is a backer of big government who used her elected position to enrich her husband's medical practice.