No. 13 seed Elise Mertens rallied from a break down in each of the final two sets to eliminate No. 3 seed Simona Halep 4-6, 7-5, 7-5 and advance to the quarterfinals of the Mutua Madrid Open on Tuesday. Mertens, of Belgium, needed two hours and 34 minutes to defeat the Romanian on the clay courts of Spain. It was Mertens' second win in six attempts against Halep and her first on clay.