Former GOP presidential candidate Mitt Romney failed to secure the Utah Republican Party's nomination for Senate on Saturday, triggering a June primary.

In the final round of voting at the party's convention, state Rep. Mike Kennedy (R) won 50.88 percent of the vote, with Romney following with 49.12 percent.

Because neither candidate secured 60 percent, the two will head to a June statewide Republican primary.

Romney and Kennedy are running to succeed retiring Sen. Orrin Hatch (R).

Saturday's defeat was a surprising turn for Romney, whose national profile far exceeds Kennedy's and who could count on a strong donor network and the endorsement of prominent Republicans, including Hatch and President Trump.

When he made his bid official, Romney was considered a virtual lock for the GOP nomination and was not expected to face a serious primary challenger.

Kennedy was first elected to the Utah state House in 2012.

Romney's Senate bid, in contrast, is only the latest step in a long political career.

A former Massachusetts governor, he ran for president in both 2008 and 2012. He failed to secure the nomination his first time, losing to Sen. John McCain (R-Ariz.), but won the GOP contest in 2012. He fell to former President Obama in the general election.

In 2016, Romney made waves again when he urged Republicans to oppose Trump. He called Trump a "fraud" who lacked the character to be president.

After Trump's election there was a brief thaw as the two dined publicly and Romney was floated as a potential secretary of State. But Romney was passed up for the post, which went to Rex Tillerson.

Romney has since criticized the president over a number of issues, including his response to the violence in Charlottesville, Va.

Trump also urged Hatch repeatedly to run for reelection, a move that was widely seen as an effort to keep one of the president's most vocal critics out of the Senate.

But after Hatch announced he would retire and Romney entered the race, Trump backed the presumed front-runner. In a tweet in February, Trump said Romney would make a great senator.

That contentious relationship is likely to be tested again in the run-up to the June Utah GOP primary.

Romney made headlines earlier on Saturday when he said he was not ready to endorse Trump for reelection in 2020, telling CNN he would "make that decision down the road."

"As a person of political experience, if I endorse someone, I'll want to know what's in it for Utah and what help would he provide for us on key priorities in Utah."

"I'm not a cheap date," he added.

This story was updated at 10:06 p.m.