WASHINGTON — Curt Clawson, a businessman who was little known months ago in Southwest Florida, won a contentious GOP primary Tuesday to fill the U.S. House seat left open by the scandalous downfall of Trey Radel.

Clawson, 54, pitched himself as an outsider against more established candidates and was embraced by the tea party. He poured more than $2 million into television ads. In one, the former Purdue basketball player challenged President Barack Obama to a three-point contest.

The Bonita Springs resident took about 38 percent of the vote in the Congressional District 19 race, besting several rivals, including state Sen. Lizbeth Benacquisto, whose swift rise to prominence in Tallahassee made her an establishment favorite. Benacquisto was fighting for second place with former state Rep. Paige Kreegel.

"I got into this race because I felt like we needed more outsiders in Congress," Clawson said in a tweet. "The career politicians aren't getting the job done."

Clawson has to run in a general special election set for June 24 but enters as the favorite against Democrat April Freeman; the district is solidly Republican.

He would replace Radel, who was elected in 2012 and made a name for himself among Washington reporters for his incessant use of social media. Then Radel was arrested buying cocaine from an undercover police officer in Washington. Radel pleaded guilty to a misdemeanor and eventually resigned amid widespread calls to do so.

More than $6 million was spent on the primary, with Clawson leading the way. Several super PACs also got involved, helping add to the negative tone, and raising questions about close ties to candidates.

Clawson outlasted scrutiny of his record as an automotive industry executive and a TV report about a sex offender that lived in one of Clawson's homes, sold just before he entered the race.

As Clawson climbed in the polls, he drew support from former Rep. Connie Mack, who held the seat before Radel, and U.S. Sen. Rand Paul, R-Ky. The Tea Party Express gave him another boost. The group on Monday was feeling bullish about Clawson's chances, proclaiming the race was the "first tea party vs. establishment showdown" of 2014.