Serena Williams put up both hands after a sending a forehand long and high over the baseline in the first set. She wanted nothing to do with yet another unforced error in her Australian Open final against Angelique Kerber.
For the second time in as many majors, nerves got to Williams as she tried to equal Steffi Graf's Open-era record of 22 Grand Slam singles titles.
No. 7-seeded Kerber had never played in a Grand Slam final and had lost five of her six career meetings with Williams, but she responded with a stunning 6-4, 3-6, 6-4 upset win over the six-time Australian Open champion.
Williams had won the title every previous time she'd reached the final at Melbourne Park, and was overwhelming favorite to continue that streak against Kerber, who joked she was "one leg in the plane to Germany" when she faced match point in her first-round win over Misaki Doi.
"I mean, every time I walk in this room, everyone expects me to win every single match, every single day of my life," Williams said in her post-match news conference. "As much as I would like to be a robot, I'm not. I try to."
Williams opened with an impressive service game, without dropping a point, but left-hander Kerber held her ground and then broke for a 2-1 lead. She broke again in the seventh game as Williams' unforced error count rose.
The 28-year-old Kerber used acute angles to keep Williams guessing, and continually passed the 21-time major winner or forced errors at the net.
And she had five service breaks — two in the first, and three in third set — against Williams, who hadn't dropped a set in the previous six rounds.
"My whole life I was working really hard and now I'm here and I can say I'm a Grand Slam champion," said Kerber, who had only ever reached the semifinals twice at the majors and hadn't gone beyond the quarterfinals since Wimbledon in 2012. "It sounds really crazy and unbelievable."
She is the first German woman to win the Australian title since Graf in 1994, and is projected to rise to No. 2 in the rankings next week.
Williams admitted previously she became nervous and was stalled for a while trying to get to 18 major titles, to equal Chris Evert and Martina Navratilova's career marks in second spot in the Open Era. For three majors, she didn't reach the quarterfinals, but when she finally won her 18th, it triggered a roll of four straight major titles.
Now she's been stuck on 21 since Wimbledon.
Williams won the Australian Open, French Open and Wimbledon titles last year before losing to Roberta Vinci in the U.S. Open semifinals. She was so close to a calendar-year Grand Slam in 2015, but now has no chance to push for that honor in 2016 after losing the first major of the year.
Despite a rash of uncharacteristic unforced errors, Williams made Kerber push all the way.
She had a chance to serve for the match at 5-3 in the third but couldn't hold. Williams, so used to coming back from seemingly losing positions, had a chance to level the third set but dropped her serve. It finished when she hit a forehand volley long on championship point, her 46th unforced error of the match.
Kerber dropped her racket on the court and lay flat on her back as Williams walked around the net to embrace her.
"Let me be the first to congratulate you," Williams said in her on-court speech. "Enjoy the moment. I'm so happy for you."
Told later that she appeared to be as happy about the result as Kerber, Williams said: "Really, I should get into acting!"
But, she added, "I was really happy for her. She's been around a long time. She had an attitude that I think a lot of people can learn from — to always stay positive and never give up."
"If I couldn't win, she said, "I'm happy she did."
Kerber had cried as she walked over to her support team, after the match, then back to the center of the court with one arm raised.
At the ceremony, she was all smiles again.
"You are really an inspiration for so many people, so many young tennis players," Kerber said in tribute to Williams. "You created history, you are a champion, you are a really an unbelievably great person, so congratulations for everything you did already."