Mazzei pulled out the GOP runoff win with 50.3% of the vote compared to Drummond's 49.7%, according to the Associated Press.

Trump-backed Mike Mazzei finished the primary less than one percentage point behind Gentner Drummond, who has disagreed with Trump on tariffs.

Tulsa businessman Mike Mazzei is hoping to win a hotly contested Republican primary runoff for Oklahoma governor against state Attorney General Gentner Drummond.