Republican presidential candidate John Kasich is projected to win the Ohio primary, knocking off rival Donald TrumpDonald TrumpClinton vows to appoint trade prosecutor to fight bad policies Clinton lauds Warren in first joint appearance Former Bush national security official backing Clinton over Trump MORE to secure a critical victory that increases the likelihood of a contested convention.
Kasich's win gives him all 66 of the state's GOP delegates.
Fox News and CNN called the race at about 8:45 p.m. EDT, just over an hour after polls closed.
Kasich got a late assist on the trail from 2012 GOP presidential nominee Mitt Romney, who campaigned at his side.
And rival Marco RubioMarco RubioRubio challenger takes aim at Senate reversal in new ad Juan Williams: GOP sounds the sirens over Trump Colorado GOP Senate race to unseat Dem incumbent is wide open MORE, who had practically no chance iof taking n Ohio, had told supporters in the state to vote for Kasich to try to keep the state's delegates out of Trump's hands.
Trump's loss makes it tougher for the businessman to clinch the nomination outright before the GOP convention. He gains no delegates from Ohio because of the winner-take-all rules.