The German is just the third southpaw to hold the WTA's No.1 ranking.
The German pulled off two amazing improvisational shots during second-round action in Stockholm.
Hall of Famer recognizes rival's contributions.
Feliciano Lopez, Grigor Dimitrov and Milos Raonic recall life-altering decisions.
The ultimate rivals are enthusiastic allies.
The world No.12 will become a brand ambassador.
According to Tennis Australia the 21-year-old will seek help to reduce his ban from eight weeks to three.
