Leg injury ends world No. 1's Australian Open hopes.
The No.4-seed fell to 0-3 lifetime in major quarterfinals amidst health concerns.
Hyeon Chung has gone from longshot to Oz Open top contender.
Team contributions have been key to Roger Federer's singles success.
Former No. 1 sees big things for AO conqueror.
No. 2 seed's skillful improv shot.
The German gets some sage advice from the maestro.