Jan Kumstat will advance against Matheus Pucinelli de Almeida in Hamburg on August 15, 2026. The 19-year-old will topple the 25-year-old despite Pucinelli’s 54-35 career record and his 36-19 clay court numbers, as Kumstat brings a 27-13 career mark and a 19-7 clay record. A victory will vault Kumst…