The United States has already recorded more deaths than any other nation, with nearly 800 more fatalities on Tuesday taking its toll past 121,000.
The indomitable Serb stretched his unbeaten streak this season to 13 by rallying from two sets to one down and beating the courageous fifth-seeded Austrian...
The Serbian world number two, despite trouble with his contact lenses, he is targeting an eighth Melbourne Park crown and 17th Grand Slam title.
The six-time champion's reward is a showdown against either long-time rival Novak Djokovic or big-serving Canadian Milos Raonic.
"It is quite unreal to be two match points down to come back and strange to play a tie-break at 12-12. I was hoping to get to the tie break," he said....
Djokovic, twice a champion in the principality, lost serve five times in a 6-3, 4-6, 6-2 defeat by Russia's 10th seed Medvedev.
The Serb was in total control on his own delivery and won his first four service games without conceding a single point
The Serbian star led a parade of the top four seeds into the last eight.
"I would like to try and stay there, obviously. It's taken a huge effort the last five, six months to get there."
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