(Adds Williams quotes)
LONDON, July 1 (Reuters) - German Sabine Lisicki sent another seismic shockwave through Wimbledon on Monday when she dumped five-times champion Serena Williams out of the tournament with a 6-2 1-6 6-4 fourth-round upset.
Top seed Williams, overwhelming favourite for the title with her chief rivals already out, squandered a winning position as the resilient Lisicki, no novice on a grasscourt after reaching the 2011 semi-finals, refused to capitulate in front of a stunned Centre Court crowd.
Williams appeared to have averted danger when she reeled off nine successive games to lead 3-0 in the decider but Lisicki rallied with a gripping fightback.
After breaking to nose 5-4 ahead, the 23rd seed showed no stage fright by securing victory on her second match point to set up a last-eight meeting with Estonian Kaia Kanepi.
"I am still shaking, I am so happy," Lisicki told the BBC as Williams followed second and third seeds Victoria Azarenka and Maria Sharapova out of a championship that is confounding expectations.
"Serena played a fantastic match, she is such a tough opponent. It is an amazing feeling to win this match. This is such a special place for me and the crowd were brilliant to me.
"I gave it everything I had, I fought for every single point to try to win it somehow. I'm not thinking about the next match yet."
After dropping just 11 games in the first three rounds, her surprise exit, which mirrored those of former men's champions Roger Federer and Rafa Nadal last week, ended Williams's win streak at 34 matches. It was only her fourth loss in the last 76.
"She played a super aggressive game. When you're playing and you have absolutely nothing to lose, it's like you can really play with so much freedom and so loose. That's how she played today," Williams told reporters.
"I didn't play the big points good enough. I didn't do what I do best. I think I had a little hesitation, and that explains it."
Lisicki took advantage of a somewhat sluggish Williams to seize the first set, her strong serve and fizzing groundstrokes at times leaving the multiple grand slam winner rooted to the spot.
The American, aghast, annoyed and berating herself after each error, desperately searched for the missing aggression and from 1-0 down in the second, reeled off nine games in a row.
She made no unforced errors to breeze through the second set and appeared to have knocked the stuffing out of her reeling opponent.
But the doubts began to creep back into her game as each time she appeared to be in control, the German answered with breaks of her own before Williams dropped her serve to trail 5-4.
Williams saved one match point, then wasted a break point of her own before Lisicki sealed the biggest victory of her career with a rasping forehand winner. (Editing by Ed Osmond)