Team GB's men's 4x400m relay team have qualified for tomorrow's night final at the London Olympics.
Williams moved the team up to third, while Jack Green then produced his quickest-ever run over that distance to hand Marytn Rooney the baton in first place.
Rooney ran a safe final lap, eventually crossing the line at the same time as his counterpart from Trinidad in 3:00.38.
The Belgian squad claimed the final automatic qualification spot.
There was not such good news for the Oscar Pistorius and his South African teammates though, as they failed to get the baton all the way around.