Top seed Jannik Sinner reached the quarter-finals at the Halle ATP grass event in Germany on Thursday but only after a big battle with Hungary’s Fabian Marozsan. The Italian won 6-4, 6-7 (4-7), 6-3. He pulled away in the decider, taking a 5-1 lead before losing serve and then recovering. The Australian Open champion and world number one will face Jan-Lennard Struff on Friday after the German surprised Greek Stefanos Tsitsipas. The 34-year-old won 6-4, 6-4 having converted his first match point. In another minor shock, Italy’s Matteo Berrettini was beaten in three sets by American Marco Giron. …