Attorney Kevin Calvey and youth camp director James Lankford topped the Republican field vying to replace Rep. Mary Fallin (R-Okla.).

Calvey and Lankford took 34 and 32 percent of the vote, respectively, in the seven-way race for the 5th district nomination and will head to a runoff. Fallin left her Oklahoma City seat after two terms to run for governor. She claimed the GOP gubernatorial nod earlier in the evening.

The Associated Press, meanwhile, declared attorney Billy Coyle the winner of the Democratic nomination, with 57 percent of the vote.

On the GOP side, state Rep. Mike Thompson finished a disappointing third, with 17 percent of the vote.

Thompson had raised the most of the top three candidates, pulling in $910,762 for the cycle. He also spent heavily on TV advertising and had only $266,447 left as of his pre-primary filing.

Calvey spent less but went up with his buy early, airing ads on Fox News. Calvey, a former state lawmaker, also benefited from a higher name recognition because he ran for the seat in 2006. He raised $628,560 during the cycle and had $325,439 left in bank, according to his July 7 report.

Lankford, a political newcomer, was considered to have some momentum going into Tuesday’s vote. He raised $375,571 and had $92,167 cash on hand in his last Federal Election Commission filing.

The candidates sought to portray themselves as being the most conservative, all vowing to curb government spending and repeal the healthcare reform bill.

This isn’t the first time a primary in the 5th district has gone to a runoff. In 2006, Fallin topped a field of five candidates, but failed to break 50 percent. She went into the runoff against Republican Mick Cornett, whom she handily defeated. 

Oklahoma’s runoff will happen Aug. 24. The winner of the GOP nomination is expected to keep the seat in the Republican column. 

—Updated 10:14 p.m.