Grenada's Kirani James signalled his intention to add Oympic gold to the 400m world title he claimed last year with a convincing victory at the Boston Indoor athletics meeting. James clocked 45.96sec, fastest in the world so far this year, as he again demonstrated that US dominance of the men's Olympic 400m is under threat. James posted an emphatic victory over American Josh Scott (46.54), Trinidad's Renny Quow (46.70) and the Virgin Islands' Tabarie Henry (46.88). "Considering this was my first indoor meet of the year, I have to be happy with winning here in pretty good time," James said. "I feel a lot stronger than in the past. I've put in a lot of work in the weight room, not done all that much on the track. "To open the season running 45.96, I guess that's pretty good," the 19-year-old said. James, who won the 400m world title last year in Daegu, South Korea, is hoping to continue to build toward London with a strong performance at the World Indoor Championships March 11-12 in Istanbul. If he does eventually top the Olympic podium, he'll reverse a trend of US success in the event. Americans have won seven consecutive Olympic titles in the 400m -- LaShawn Merritt in 2008, Jeremy Wariner in 2004, Michael Johnson in 1996 and 2000, Quincy Watts in 1992, Steve Lewis in 1988 and Alonzo Babers in 1984. "There are so many other good 400 men everywhere, and I know anything can happen, but right now things are looking pretty good," he said. American Jenn Suhr rebounded from a disappointing no-height at the US Open at Madison Square Garden last week with a victory in the women's pole vault with a clearance of 4.88m. That was an American indoor record and put her second on the world all-time indoor list behind reigning two-time Olympic champion Yelena Isinbayeva of Russia. Ciaran O'Lionaird of Ireland turned the tables on a strong international field to win the men's mile in 3:56.01. Canada's Taylor Milne was second in 3:56.40 and American Galen Rupp third in 3:57.10. Also under the four-minute mark was Britain's Mo Farah, the outdoor world 5,000m champion. Farah was fourth in a personal best of 3:57.92, despite the fact that he was tripped on the first of eight laps and lost at least 15 meters on the field. "I was kind of stunned when it happened," Farah said. "I just got back up as quickly as I could and started chasing everybody. To run that fast in a race like that, well I guess that's a pretty good sign of my fitness."