WIMBLEDON, England -- Venus Williams would shank a shot -- and she shanked many on this day -- then turn toward the Court 1 player guest box where her parents were seated and put her palms up or shrug her shoulders, as if to indicate, "I don't know what's happening here."
The five-time Wimbledon champion was out of sorts, out of answers and out of the tournament in the quarterfinals, stunned 6-2, 6-3 Tuesday by the lowest-ranked woman left, No. 82 Tsvetana Pironkova of Bulgaria.
Williams double-faulted five times and totaled 29 unforced errors, 23 more than her solid-if-not-spectacular opponent.
"Didn't do myself any favors," said the No. 2-seeded Williams, whose younger sister, No. 1 Serena, won Tuesday to reach the semifinals. "I missed all shots today: forehand, volley, backhand. You know, if there was a shot to miss, I think I missed it."
It was the older Williams' 77th career singles match at the All England Club -- she participated in eight of the past 10 finals, losing to her sister three times, including in 2009 -- and never had she won so few games. The only time she's been beaten at Wimbledon by someone ranked lower than Pironkova was all the way back on June 28, 1997, when the American lost her tournament debut to No. 91 Magdalena Grzybowska.
Really, the only factor preventing this result from truly being considered one of the biggest upsets in tennis history is that Pironkova actually managed to do this before: She defeated Williams at the 2006 Australian Open.
"No one expected me to (reach a) semifinal in Wimbledon," Pironkova said, "and to beat Venus Williams like that."
On Thursday, Pironkova will face No. 21 Vera Zvonareva of Russia, who added to the topsy-turvy day by coming back to oust No. 8 Kim Clijsters 3-6, 6-4, 6-2.
Unlike Pironkova, Zvonareva at least can boast of some experience at this stage, having reached the 2009 Australian Open semifinals.
On the other side of the draw, defending champion Serena Williams smacked 11 aces -- lifting her total for the tournament to a Wimbledon-record 73, one more than she hit last year -- and made only six unforced errors in a 7-5, 6-3 victory over No. 9 Li Na of China.
"I haven't seen her serve that well in a while," said the Williams sisters' mother, Oracene Price, who joked that "they're stealing some aces from Serena; we're counting."
She next faces yet another unheralded member of this year's final four, 62nd-ranked Petra Kvitova of the Czech Republic, who saved five match points and erased third-set deficits of 4-0 and 5-2 to eliminate 80th-ranked qualifier Kaia Kanepi of Estonia 4-6, 7-6 (8), 8-6.
Asked if she thinks she can win the title, the 20-year-old Kvitova replied: "I don't think so. No."
Serena Williams is the only remaining woman with a Grand Slam championship; she owns 12.