Li Na made a triumphant night-time debut at the US Open with an impressive rout of former world No 1 Jelena Jankovic to reach the quarter-finals and match her best New York result.

Defending champion Serena Williams won her much-anticipated US Open showdown with Sloane Stephens on Sunday, while Li Na avenged a painful loss in Rome to join the world No.1 in the last eight.

The world No.1 overcame physical difficulties, emotional distress as well as a stubborn opponent in Jelena Jankovic before reaching the final of the WTA Championships with a 6-4, 2-6, 6-4 win.

In her third trip to the final at Melbourne Park, Li won the Australian Open title in January to reach a career-high No. 2 ranking, another continental milestone.

American Ann Li will meet Romanian qualifier Sorana Cirstea in the Tennis in the Land singles final, starting not before 2:30 p.m. at Nautica Entertainment Complex.

Ann Li advanced to her second WTA Tour final of the year, edging second-seeded Xinyu Wang 6-3, 5-7, 6-4 on Friday at Tennis in the Land in Cleveland.