Stefanos Tsitsipas’ rivalry with Daniil Medvedev will add another chapter after the Greek player beat Alexandre Muller 6-3, 7-5 at the Shanghai Masters on Tuesday. The 12th-ranked Tsitsipas and the Russian former U.S. Open champion will meet for a 14th time, and first in nearly a year. The fifth-ranked Medvedev has a commanding 9-4 lead in the head-to-head series, which has spilled over into a war of words off the court in the past.