Republican candidate Bradley Byrne defeated tea-party-backed opponent Dean Young in a House GOP runoff in Alabama on Tuesday. (Mike Kittrell/AP)

Republican Bradley Byrne defeated his insurgent conservative opponent in an Alabama congressional primary runoff Tuesday, notching a hard-fought victory for the business wing of the GOP.

With 100 percent of votes tallied, Byrne topped Dean Young, a Christian conservative aligned with the tea party, 52.5 percent to 47.5 percent.

The campaign marked the first big electoral test for business-minded Republicans in their showdown with the GOP’s tea party wing. Riled by the recent government shutdown and standoff over the debt ceiling, the business wing of the party decided that it was time to fight back against the tea party insurgency. Byrne, a business lawyer and former state senator, said during the campaign that the shutdown was not good for the country, while Young said it “was not the end of the world.”

The result in Alabama was one of several blows to the most conservative wing of the GOP on Election Day. Conservative Ken Cuccinelli II’s loss in the Virginia governor’s race and centrist Republican Gov. Chris Christie’s resounding win in New Jersey are sure to stoke talk in GOP circles about the party’s need to get behind more moderate candidates.

Byrne is now in the driver’s seat to succeed Republican Jo Bonner, who vacated the 1st District seat this year to take a position in the University of Alabama system. Byrne and Young were the top two vote-getters in a September primary in which no candidate won a majority of the vote.

Bonner was part of a flurry of establishment GOP support that rallied to Byrne’s side during the runoff. The U.S. Chamber of Commerce spent at least $199,000 on his behalf, while big companies such AT&T and Home Depot donated thousands to Byrne’s campaign down the stretch.

Byrne often cast himself as a “workhorse” in an effort to contrast with Young, who he characterized as a “show horse.” He urged voters to send someone to Washington not just to fight but to be an effective voice for the district.

Despite being outspent and having almost no support from national conservative groups, Young made a race of it by rallying his base of evangelical Christians and tea party voters angry with the federal government and eager for the next fight. He sought to criticize Byrne as a politician beholden to establishment interests who would mean business as usual if elected to Congress. Young cast himself as a fresh voice ready to shake things up.

For business leaders, the victory in Alabama is a much-needed boost of momentum headed into 2014, when they will be looking to elect like-minded candidates to other seats across the map, including those currently represented by tea party Republicans. Two such seats are in Michigan, where tea-party-aligned congressmen Kerry Bentivolio and Justin Amash have already drawn primary challengers.

Another possible front is in Idaho, where business groups may opt to help Rep. Mike Simpson, who has drawn a primary challenger running to his right. The anti-tax Club for Growth has lined up behind that challenger, lawyer Bryan Smith.

Byrne will face Democrat Burton LeFlore in the Dec. 17 special general election to succeed Bonner. The Republican is expected to win easily. Mitt Romney won more than six in 10 votes there in 2012.