Berlin, Germany (Sports Network) - Surging American Serena Williams posted a third-round win, while top-ranked star Justine Henin went by way of the upset Thursday at the $1.34 million German Open, a clay-court French Open tuneup. Also, second-seeded and defending champion Ana Ivanovic snuck into the quarterfinals here on Day 4.

The three-time Berlin champion Henin was stunned by 13th-seeded Russian Dinara Safina 5-7, 6-3, 6-1 on Day 4 at LTTC Rot-Weiss. The capable Safina, in the process, scored her second career victory over a world No. 1 player.

The reigning French and U.S. Open champion Henin, who has been nursing a knee injury of late, was seeing her first action since getting tattooed, 6-2, 6-0, at the hands of the high-flying Williams in a quarterfinal in Miami over a month ago. The diminutive Belgian titled here in Berlin in 2002, 2003 and 2005 and was the runner-up in 2006.

Meanwhile, a fifth-seeded former world No. 1 Williams extended her current red-hot winning streak to 17 matches by pasting 11th-seeded Pole Agnieszka Radwanska 6-3, 6-1.

The eight-time Grand Slam champion and 2002 Berlin runner-up Williams is now a dominant 21-1 this season and seeking her fourth straight tournament title. The veteran slugger hasn't lost since bowing out against Serbian Jelena Jankovic in the quarterfinals at January's Australian Open.

The Australian and French Open runner-up Ivanovic continued her winning ways in Berlin by holding off Austrian lefthander Sybille Bammer 7-5, 4-6, 6-4 in Thursday's nightcap. The Serbian Ivanovic topped Svetlana Kuznetsova in last year's finale here, but the Russian won't be making a return trip to the final this year, as the third-seeded U.S. Open runner-up Kuznetsova was sent packing by 15th-seeded Ukrainian Alona Bondarenko 1-6, 6-2, 6-2.

A fourth-seeded Jankovic straight-setted Russian Maria Kirilenko 6-2, 6-4, while seventh-seeded Russian Elena Dementieva handled her countrywoman Vera Dushevina 7-5, 6-3 and 10th-seeded Hungarian Agnes Szavay toppled eighth- seeded Wimbledon runner-up Marion Bartoli, of France, 7-5, 7-5.

Another third-round result saw Belarusian Victoria Azarenka cool off Argentine Gisela Dulko 6-3, 6-1. Dulko was last week's clay-court winner in Morocco, while Azarenka recorded a runner-up finish in Prague.

Friday's quarterfinals will pit Ivanovic against Szavay, Jankovic versus Dementieva, Williams against Safina and Bondarenko versus Azarenka.

The 2008 German Open titlist will pocket $196,900.