NEW YORK — Jelena Jankovic won another sneaker squeaker, playing 28 points in the last game to finish off Zheng Jie 7-5, 7-5 today and become the first woman into the fourth round at the U.S. Open.

The No. 2 Jankovic is aiming to reach her first Grand Slam final. She needs three more wins — with Justine Henin retired, Maria Sharapova injured, Ana Ivanovic eliminated and the Williams sisters in the opposite bracket, this figures to be her best chance.

Jankovic came out full of energy, showing no ill effects of a bad left leg that cramped after she played Wednesday. She bounded back and forth and, in her trademark style, often came to screeching stops while doing the splits to reach shots.

By her fifth and final match point, Jankovic needed a bit of a break before serving. In her previous match, she chided her opponent for not being ready to receive soon enough.

A day after top-seeded Ivanovic was upset by 188th-ranked Julie Coin, the favorites restored order to Flushing Meadows.

Fifth-seeded Nikolay Davydenko beat Agustin Calleri 6-4, 6-4, 7-6 (2), and No. 11 Fernando Gonzalez defeated Bobby Reynolds 7-6 (6), 6-4, 6-4.

Roger Federer, Novak Djokovic and Elena Dementieva were set to play daytime matches. The night session at Arthur Ashe Stadium featured Andy Roddick, along with No. 23 Lindsay Davenport taking on No. 12 Marion Bartoli.

Jankovic needed more than two hours to beat the 37th-ranked Zheng after playing for nearly three hours in the second round. Plus, the Serbian star was scheduled to play doubles later in the day.

Ahead 6-5, Jankovic took a 40-30 lead and tried to quickly close out the match. But Zheng, who won several replay challenges and benefited from many balls that trickled over the net in her favor, and her bright red shoes would not go away.

Jankovic frequently looked into her family box for inspiration while Zheng shrieked after missing easy shots. The final game went to deuce 11 times before Zheng put a routine shot into the net.

Jankovic is one of six women who still have a chance to be ranked No. 1 after the Open, with Ivanovic among them despite her loss.

Coin pulled an upset for the record books. Not since the WTA computer rankings started in 1975 had a woman ranked so low beaten a reigning world No. 1.