#NextGenATP star Jakub Mensik is quickly becoming a Top 10 menace. Will Novak Djokovic be the next player he stuns? The 19-year-old from Czechia ousted No. 10 in the PIF ATP Rankings Grigor Dimitrov 6-3, 3-6, 6-4 on Wednesday at the Rolex Shanghai Masters to earn his first Lexus ATP Head2Head meeting with Djokovic.