Mehmet Oz, celebrity physician and US Republican Senate candidate for Pennsylvania, speaks during a town hall in Bell Blue, Pennsylvania, US, on Monday, May 16, 2022.Rachel Wisniewski | Bloomberg | Getty ImagesPolls closed Tuesday in Pennsylvania’s primary elections, including a high-profile and hyper-competitive Republican fight that could play a decisive role in which party controls the U.S. Senate after the midterms.Dr. Mehmet Oz, the celebrity physician and former host of “The Dr. Oz Show,” made waves when he announced he would run as a Republican for the Senate seat being vacated by retiring GOP Sen. Pat Toomey. He received former President Donald Trump’s coveted endorsement, and his campaign has reportedly spent more than $12 million in the race on advertising alone.But Oz, a first-time campaigner who has lived in New Jersey for two decades, was neck-and-neck in the polls with two other Republicans: ex-hedge fund CEO Dave McCormick, and right-wing commentator Kathy Barnette, who surged in popularity in the final days of the primary.Whoever wins the Republican primary could face off against John Fetterman, Pennsylvania’s lieutenant governor. Both the Republican and Democratic Senate primaries were too early to call shortly after polls closed at 8 p.m. ET, according to NBC News. Fetterman is leading the Democratic pack, NBC projected. Toomey’s Senate seat could prove to be one of the most competitive in the general election, as Democrats try to maintain control of a chamber split 50-50 by party.Public polling shows Fetterman as the frontrunner against his leading rivals, U.S. Rep. Conor Lamb and state Rep. Malcolm Kenyatta.Lt. Gov. John Fetterman, U.S. Democratic Senate candidate for Pennsylvania, takes a selfie with attendees at a meet-and-greet at the Weyerbacher Brewing Company in Easton, Pennsylvania, May 1, 2022.Hannah Beier | ReutersHis Senate bid took a turn over the weekend, as Fetterman’s campaign announced that the candidate suffered a stroke and was in the hospital. Fetterman said in a statement that he expects to fully recover, though the illness kept him off the trail in the final days of the primary.Earlier Tuesday afternoon, the Democrat’s campaign said that Fetterman had completed a successful surgery to implant a pacemaker with a defibrillator. He is resting at the hospital after the procedure, which lasted more than two-and-a-half hours, according to his campaign.This is developing news. Please check back for updates.