In 2000 in Germany he won in his first appearance the International Neckar Open in Deizisau. Also in 2000, Bu defeated the Azerbaijani talent Teimour Radjabov 6½-1½ in an eight-game Future World Champions Match competition in New York. They played two games a day at a time control of one hour for all the moves. The margin of victory was a little flattering to Bu with Radjabov missing a number of good chances on the first day and then having a bit of a disaster on day two losing both games. Radjabov had beaten Bu in the two game final of a Cadet's event held earlier in the year on the Kasparovchess.com site. In May 2000, Bu made his first appearance in a United States Chess Federation-rated tournament at the New York Open in New York City. Although one of the favorites to win the tournament, he lost in the first round to American life master Shearwood McClelland III in an upset, before rallying to finish with 5½/9.