The reliably red state of Oklahoma held its primary elections on Tuesday and it was an eventful night with unexpected results for a few Republican incumbents and their challengers.

At least four incumbent Republicans in the Oklahoma state legislature, including a powerful Senate leader, were ousted by voters in favor of their outsider GOP challengers, Newsweek reported.

It should be noted that at least some, if not all, of those seats will remain in the Republican column following November's general elections, as the victorious challengers either face no opponents from other parties or are situated in strongly held GOP districts.

Some major upsets in Oklahoma's Republican primary

According to Newsweek, the most shocking outcome of Tuesday's primary elections in Oklahoma was the upset of Senate Majority floor leader Greg McCourtney, who was in line to serve as the next president pro tempore in the next legislative term.

He was defeated by Jonathan Wingard by a margin of 52-48% for the Senate District 13 seat. That primary win doubled as a general election victory for Wingard, as there were no Democrats, independents, or third-party candidates who ran for the seat.

Another upset involved incumbent state Sen. Jessica Garvin, who lost to McClain County assessor Kendal Sacchieri by a margin of 53-47%. Sacchieri will face a Democratic opponent in November while Garvin made it clear she was "not sad at all" about the loss and instead looked forward to spending more time with her family next year.

Also ousted from the Oklahoma State Senate was incumbent Cody Rogers in Tulsa's District 37, who was defeated 51-49%, or just 84 votes, by a commercial insurance agent named Aaron Reinhardt, who will go on to face an independent challenger for the seat in November.

That last of the four significant Republican primary upsets involved State Rep. John Talley, who was beaten by retired teacher Molly Jenkins by a wide margin, 60-40%. Jenkins faces no other opponent in the general election in November.

Run-off elections and narrow victories for other GOP incumbents

The Oklahoma Voice reported that in addition to those major upsets in the Republican primary, several incumbents remained locked in tight battles against challengers that were too close to call and will be decided later in run-off elections that are scheduled for August 27.

One of those involves District 32's State Rep. Kevin Wallace, who is the chairman of the powerful House Appropriations and Budget Committee, who will defend his seat for a second time in a few months against Republican challenger Jim Shaw.

A few other GOP incumbents reportedly managed to just barely avoid the added pressure and risk of a run-off election by narrowly defeating the outsiders who challenged them, such as Sen. Shane Jett in District 17, Sen. Casey Murdock in District 27, and Rep. Dean Davis in District 98.

Oklahoma's incumbent congressional delegation all cruise to victory, if they were even challenged

The tumultuous nature of the Republican primaries in Oklahoma was confined solely to the state legislature elections, however, as USA Today reported that all five Republican incumbents in Congress easily defeated their challengers -- if they even faced a challenger at all.

The 1st District's Rep. Kevin Hern secured 87% of the vote against challenger Paul Royse, the 3rd District's Frank Lucas won 73% of the vote against two GOP challengers, and the 4th District's Rep. Tom Cole earned more than 64% of the vote against challenger Paul Bondar.

The 2nd District's incumbent Rep. Josh Brecheen faced no challenger in the primary but will face Democratic and independent challengers in November, while the 5th District's incumbent Rep. Stephanie Bice also went unchallenged in the primary and will face off against Democratic candidate Madison Horn in November.