A pep talk from Roger Federer helped inspire Belinda Bencic to a major upset on the opening day of the Australian Open.
The 20-year-old knocked out last year's runner-up Venus Williams 6-3 7-5.
Twelve months after Venus was beaten by sister Serena in the final, the family will not be represented in the second round for the first time since 1997, before Bencic was even born.
She prepared by teaming up with Federer to represent Switzerland at the Hopman Cup, with the pair lifting the trophy.
Defending champion Federer offered his advice to Bencic before the match and congratulated her afterwards.
She said: "I admire that before the match he's so relaxed, being funny with his team. Then on court, he's so focused. That's the main thing I want to learn.
"Even off the court, a normal, humble person, happy and trying to give advice and help someone like me. That makes him special."
Williams said: "I don't think I played a bad match. She just played above and beyond."
Sloane Stephens lost 2-6 7-6 (7-4) 6-2 to Zhang Shuai, and 10th seed Coco Vandeweghe was beaten 7-6 (7-4) 6-2 by Hungary's Timea Babos.
French Open champion Jelena Ostapenko eased to a 6-1 6-4 victory over Francesca Schiavone, and Julia Goerges won 6-4 6-4 over Sofia Kenin, but former finalist Dominika Cibulkova was beaten 6-2 6-2 by Kaia Kanepi.