On just her second try at the US Open, 19-year-old Simona Halep notched her first win in Flushing Meadows on Day 2. But it wasn't just any win.

In advancing to the second round, she sent home reigning French Open champion Li Na in straight sets, 6-2, 7-5. It's a win that's not too surprising, considering the fact that she nearly topped then-No. 4 seed Jelena Jankovic in her 2010 debut, pushing the Serb to three sets before falling.

"It's a great win for me. It's unbelievable," Halep said. "I feel very good. I played good. I played a lot of great players before, Serena Williams in Wimbledon, Kuznetsova in Toronto. A lot of good matches for me. This one, it's my best."

The young Romanian, who won the 2008 junior French Open title and is currently ranked No. 53 in the world, is well on her way to setting new career-highs. She has so far reached the quarterfinals at Auckland, the finals at Fes and the third round of the Australian Open this year. In Melbourne, she took out two seeded players in No. 12 Agniezka Radwanska and No. 24 Alisa Kleybanova.

Halep's consistent game helped propel her past the 29-year-old Grand Slam champion from China, as the Romanian hit only 19 unforced errors to Li's 54.