BEIJING — The dramatic ascendance of Usain Bolt as the world’s greatest sprinter continued Wednesday night at the Beijing Olympics as he left another group of elite runners far behind in setting a world record in the 200 meters and winning his second gold medal. Having obliterated the world record in the 100 on Saturday, he is the first man to win the 100 and 200 at the same Olympics since Carl Lewis in 1984.Starting in Lane 5, Bolt took the lead in the first 50 meters and won in devastating fashion, pulling away from the field and winning by several meters in a time of 19.30. Michael Johnson had held the record of 19.32, set in 1996 at the Atlanta Games.Churandy Martina of the Netherlands Antilles won the silver. Wallace Spearmon of the United States finished third, but as he began a victory lap while draped in an American flag, he learned that he had been disqualified for stepping into the lane of his teammate Walter Dix. Shawn Crawford, also of the United States, ended up with the bronze.The United States filed a protest over Spearmon’s disqualification. Televised replays showed Spearmon stepping on the line several times.With the Chinese hurdler Liu Xiang out of the Games with an injury, leaving the Bird’s Nest stadium without the main attraction, Bolt and his fellow Jamaican sprinters have turned the venue into their own showcase. Bolt first stole the show in his Olympic final debut Saturday, delivering the record-setting performance in the 100 — in 9.69 seconds — despite beginning his celebration well before the finish line. The next night, three Jamaican women swept the medals in the 100. SOURCE:NYT.COM