MELBOURNE, Australia — A Grand Slam tournament that had already taken one big unexpected turn became a genuinely wild ride on Sunday as Andy Murray and Angelique Kerber, the world’s two No. 1 singles players, were beaten by unseeded opposition in the fourth round and Roger Federer continued to do an excellent impression of vintage Roger Federer.
The first week of this Australian Open has been one of the most surprising starts to a major tournament in recent years, with the six-time Australian Open champion Novak Djokovic losing to Denis Istomin in the second round and Murray losing to Mischa Zverev on Sunday.