MELBOURNE, Australia — The danger can come from anywhere at this stage, as Serena Williams proved two weeks ago with an early loss in Auckland, New Zealand, after making 88 unforced errors in the wind against the young American Madison Brengle.
The risk of a stumble was clear from the start on Tuesday in Williams’s opening match at the Australian Open. Across the net in Rod Laver Arena was Belinda Bencic, the 19-year-old Swiss with the precociously elegant game who already had upset Williams in their most recent match.