Former champion Li Na knocked out by Mattek-Sands PARIS (Reuters) - China's only grand slam singles champion Li Na was bundled out of the French Open by American Bethanie Mattek-Sands on Thursday, losing a rain-interrupted match 5-7 6-3 6-2. Sixth seed Li, who became a flagbearer for Asian tennis in 2011 when she won the French Open, edged the first set but after two lengthy rain breaks her game fell apart. Mattek-Sands, wearing knee-high black socks, resumed after the second interruption 4-3 ahead in the second set and then reeled off seven games in a row. Li eventually stopped the rot to break serve as Mattek-Sands served for the match at 5-0 and then held her own to reduce the deficit but her revival came too late. With rain still falling and play stopped on many other courts the 66th-ranked American held her nerve and sealed victory when her opponent netted a forehand. Li refused to make excuses for her defeat. "I know for sure that I don't normally lose seven games in a row," she told reporters. It was very tough conditions, coming back to the court three times. But for both players it was the same. I should find out what happened and I'll talk to myself, my team to see what happened. Reporting by Martyn Herman, editing by Justin Palmer