Mario nabs top spot on "Dancing with the Stars" last night!

R&B singer Mario nabbed the top score of 24 out of 30 for his cha-cha on last night’s Dancing with the Stars premiere. But mastering his moves wasn’t easy. “Oh man, I pulled my groin!” he told Usmagazine.com backstage after last night’s show in L.A. “I was like great balls of fury!” His partner Karina Smirnoff wouldn’t cut him any slack: “She still made me dance!” he complained.