World number one Serena Williams saw her winning streak and hopes of a sixth Wimbledon title end with a shock defeat by Germany's Sabine Lisicki.
Lisicki, the 23rd seed, won the fourth-round encounter 6-2 1-6 6-4 on Centre Court.
Williams joins leading names Maria Sharapova, Victoria Azarenka, Roger Federer and Rafael Nadal in making an early exit at what has been a tournament of stunning upsets.
It was only the third defeat in the last year for Williams, and ends her career-best winning run of 34 matches, but she insisted afterwards: "It's not a shock.
"She plays really good on grass. She has a massive, massive serve, so going in there you have to know that it's definitely not going to be an easy match playing her at Wimbledon, especially on Centre Court.
"It's definitely not a shock. I just need to do better."
Lisicki moves on to the quarter-finals for the fourth time and in each of those Wimbledon campaigns she has beaten the French Open champion.
The 2011 Wimbledon semi-finalist was overcome with emotion after a famous win and struggled to hold back the tears during a television interview.
"I'm still shaking, I am so happy," she told BBC Sport.
"Serena played fantastically all match. She is such a tough opponent. It's just an amazing feeling to win this match.
"The crowd were amazing, thanks to them for their support. They were amazing. I love this court so much, it's such a special place for me."
Lisicki's record on grass, based around the second-biggest serve in women's tennis, meant she had always looked among the most likely candidates to challenge Williams.
The 23-year-old from Troisdorf fought off four break points and took advantage of a rash of Williams unforced errors as she broke twice to win the opening set.
Williams, 31, was not about to go quietly and roared back in the second, winning 14 points in a row at one stage and not making a single unforced error as she levelled, winning it 6-1.
The American was on a roll and did not need any luck but from 40-0 down, two net cords helped her to an early break in the decider.
When Williams racked up her ninth straight game to move 3-0 clear, it was turning into a procession, but Lisicki stuck to her task.
The German got the better of three breaks in a row as she fought back from 4-2 down, thrilling the 15,000 spectators on Centre Court.
Williams had been in the ascendancy for well over an hour, but at 4-4 in the final set she found herself facing break points and, stretched to the limit, the champion could not control a smash, which flew over the baseline.
One more service game was required by Lisicki, and it was never likely to be straightforward.
After being pegged back to 30-30, she blasted long on her first match point and double-faulted to offer up a break point for Williams, but the German's serve came to her rescue.
When a second chance to clinch the win of her life arrived, Lisicki played a fearless rally, pounding away from the baseline until Williams could no longer cover the gaps and had to watch as a forehand flew past her.
"I felt that I was on the verge of winning," Williams added. "I felt really good and really confident.
"At that point I just was physically unable to hold serve. My first serve percentage was going down.
"For me, I have to be able to serve well, especially on this court, and especially going up against such a really, really strong server like Sabine."
Sabine Lisicki  v Kaia Kanepi
Li Na  v Agnieszka Radwanska 
Sloane Stephens  v Marion Bartoli 
Kirsten Flipkens  v Petra Kvitova