Romania's greatest champion will try to lead nation back to World Group.
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.