Republicans Bradley Byrne and Dean Young advanced to a primary runoff in Alabama's 1st district special election Tuesday, setting the stage for a showdown between a tea party-backed underdog and a front-running Republican who lost a tough gubernatorial race in 2010.

With about six in 10 precincts reporting, the Associated Press called the GOP race in favor of Byrne and Young. Byrne was leading the field of nine candidates, with 33 percent of the vote. Young was second with 25 percent of the vote. The runoff was triggered because no candidate was on pace to win more than 50 percent of the vote.

Republican Jo Bonner resigned the 1st district seat in August for a job in the University of Alabama system, triggering a special election. The district is heavily conservative, and is expected to stay in GOP hands.

Young, who enjoys strong tea party support, lost to Bonner in 2012. Byrne, a former state senator and the frontrunner headed into Tuesday, ran for governor in 2010, losing to now-Gov. Robert Bentlely (R) in a runoff.

The runoff will be Nov. 5, with the special general election set to follow on Dec.17. Burton LeFlore won the Democratic nod, but isn't expected to pose any real threat to the eventual Republican nominee.