TOKYO — Top-seeded Jelena Jankovic of Serbia overpowered Italy's Flavia Pennetta today to advance to the quarterfinals of the Pan Pacific Open.

Jankovic, playing her first match of the tournament after a first-round bye, coasted to a 6-2, 6-1 win over Pennetta at Ariake Colosseum.

Jankovic is No. 2 in the world rankings and played up to her billing. She broke Pennetta with a backhand down the line to go up 2-0 in the second set and closed out the match with a blistering ace.

If she wins this tournament, Jankovic would return to No. 1 in the WTA rankings, replacing Serena Williams in the top spot.

"It's a goal of mine to return to the top spot," said Jankovic. "You can go back and forth between the top three spots, but it's always nice to finish at No. 1."

Jankovic will face Svetlana Kuznetsova in Friday's quarterfinal. The fifth-seeded Russian defeated Japan's Ayumi Morita 6-1, 6-1.

In an earlier match, Olympic gold medalist Elena Dementieva of Russia defeated France's Alize Cornet 6-0, 6-3 to reach the quarterfinals.

Third-seeded Dementieva, who also had a first-round bye, broke Cornet's serve in the final game to close out a convincing win.

Dementieva, who won this tournament in 2006, will next face the winner of Thursday's later second-round match between Slovenia's Katarina Srebotnik and Francesca Schiavone of Italy.

Dementieva defeated compatriot Dinara Safina 3-6, 7-5, 6-3 to win the singles gold medal at the Beijing Olympics.

Sixth-seeded Agnieszka Radwanksa of Poland defeated France's Marion Bartoli 6-2, 6-3.