Flushing Meadows, NY -- (Sports Network) - Tropical Storm Hanna wreaked havoc on the schedule for the U.S. Open on Saturday, suspending play during one men's semifinal while forcing the postponement of the women's final.

American Serena Williams and Serbian Jelena Jankovic will square off at 9:00 p.m. (et) on Sunday instead of Saturday night, thanks to Hanna's torrential rain.

The fourth-seeded two-time champion Williams reached her fourth U.S. Open final by dominating sixth-seeded Russian Dinara Safina 6-3, 6-2 in Friday's second semifinal at Ashe Stadium. She will seek her ninth major title, going 8-3 in her previous Grand Slam finals, and appear in her first U.S. Open final since 2002.

In the first semi Friday, the second-seeded Jankovic handled fifth-seeded Russian Elena Dementieva 6-4, 6-4. Jankovic was ranked No. 1 for only one week just last month. The 23-year-old Jankovic will now appear in her first-ever major final after going 0-4 in her previous Grand Slam semis, including 0-2 in such encounters this season. She was a semifinalist here two years ago.

Serena and Jankovic have split six career matchups, including two meetings this year. The American prevailed in a final in Miami, while the Serb came out on top in an Aussie Open quarterfinal back in January. Williams topped Jankovic in an Aussie Open encounter last year, as the two players are 1-1 in their Grand Slam matchups.

The Williams-Jankovic winner will become the new No. 1 player in the world, and the 2008 U.S. Open champ will pocket $1.5 million, while the runner-up will collect $750,000.