Stuttgart - Belarussian teenager Victoria Azarenka upset Olympic champion Elena Dementieva of Russia 7-6 (8-6), 3-6, 6-1 on Friday in the quarter-finals of the Porsche Grand Prix.
The unseeded Azarenka, 19, saved a setpoint in the first-set tiebreak and then fully dominated the final set for victory in a marathon match which lasted 2 hours 53 minutes.
Dementieva saved three match points at 5-0 before hitting a backhand into the net on Azarenka9s fourth chance in the next game.
"I just kept on fighting. We had many long rallies, I tried to fight for every ball. I was playing very good," said Azarenka.
Azarenka, who has one of the loudest grunts on the women9s circuit, had lost the previous two matches against Dementieva in straight sets.
In the semi-finals on Saturday, she meets China9s Li Na or the 2006 champion Nadia Petrova of Russia.
The other quarter-finals were due to be new world number one Jelena Jankovic of Serbia vs seventh seed Vera Zvonareva of Russia and tournament number three Dinara Safina vs sixth seeded Wimbledon champ Venus Williams of the US. (dpa)
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