Shahar Pe'er's poor form continued at the USOpen on Monday when she was knocked out of the Grand Slam in the first round by Chinese star Na Li 6-2, 0-6, 1-6. After breezing through the first set, the 21-year-old Israeli lost her concentration and won only one game in the following two sets. Pe'er will be severely disappointed after reaching the quarterfinals at Flushing Meadows a year ago. While Li had a fantastic Olympic tournament, where she only just lost out on a medal in the bronze playoff after beating Venus Williams on the way to the semifinals, Pe'er was defeated in the second round. The Israeli female number one will at least have another chance to pick up a win when she teams up with Victoria Azarenka in the doubles tournament later this week. Both Li and Pe'er had similar first serve percentages of around 70 percent but the Israeli had five double faults compared to her opponent's three and Li served three aces while Pe'er served none. Israel's participation in the US Open continues on Tuesday when Dudi Sela faces Russia's Nikolay Davidenko in the first round of the men's singles tournament.