Indian Wells - Sabine Lisicki was too strong for defending champion Flavia Pennetta on Thursday, saving three match points in a three-set win over the Italian to book her Indian Wells semi-final berth.
Pennetta had hoped to repeat her surprise victory of last year, and managed to save one match point before running out of gas in the marathon quarter-final, won 6-4, 6-7 (3/7), 7-6 (7/4) by the 24th seed from Germany.
Former Wimbledon runner-up Lisicki needed two hours and 40 minutes to fashion the victory, which set up a clash with another former champion, Serbian Jelena Jankovic.
"Everything happened tonight," Pennetta said. "Match point for one, match point for the other one.
"Tennis is like this. I'm happy about the match, but of course I am upset, because when you are there, you want to win it."
After dropping the first set, Pennetta saved a match point in the 10th game of the second. She went on to take the game three points later to even the set at 5-5.
Lisicki clinched the victory in dramatic fashion with her fifth ace of the match in the third-set tiebreaker. She celebrated by letting go of her racquet and dropping to her knees before going to the net for a long embrace with her equally-exhausted opponent.
Lisicki won 75 percent of her first-serve points and broke Pennetta four times.
"In matches like this both players played unbelievable points. It was fun to be part of a match like this," said Lisicki, who owns the WTA record for the fastest serve - 210.82km/h blast she hit last year in Stanford.
She saved three match points in the 10th game of the final set after Pennetta had taken a 15-40 lead.
Lisicki fought off two match points to tie it up 40-40 then faced a third but was able to use her potent serve to get out of trouble.
Jankovic, in contrast, barely broke a sweat in 45 minutes as she advanced when qualifier Lesia Tsurenko retired in the second set with an injury.
Jankovic, who won the Indian Wells title in 2010, was leading 6-1, 4-1 when Tsurenko packed it in with a right ankle injury
"It's never nice to end a match that way," said Jankovic, who celebrated her 30th birthday last month. "In the first set I was feeling pretty good out there. I was playing my game and waiting for my chances to execute.
"In the second set she started limping and I saw that she had some problem."
Jankovic hammered one ace, only lost two points on her second serve and broke Tsurenko four times.
Tsurenko, of Ukraine, had five double faults, made 27 unforced errors and hit just seven winners.
Jankovic has always felt confident and comfortable playing in the California desert. In 2010, she defeated Caroline Wozniacki in the final but has only won one tournament since then, in 2013 in Bogota.
Jankovic, who is aiming for her 14th career title, beat rising star Belinda Bencic 6-3, 3-6, 6-3 in the fourth round.
Tsurenko was the first qualifier to reach the quarter-finals since Gisela Dulko in 2004.
The second women's semi-final on Friday features world number one Serena Williams facing third seeded Simona Halep.
Results at the ATP and WTA Indian Wells tennis tournament on Thursday (x denotes seeding):
Novak Djokovic (SRB x1) bt Bernard Tomic (AUS x32) walkover
Andy Murray (GBR x4) bt Feliciano Lopez (ESP x12) 6-3, 6-4
Jelena Jankovic (SRB x18) bt Lesia Tsurenko (UKR) 6-1, 4-1 retired
Sabine Lisicki (GER x24) bt Flavia Pennetta (ITA x15) 6-4, 6-7 (3/7), 7-6 (7/4)