Jefferson-Wooden completes world sprint treble with US relay win

Melissa Jefferson-Wooden became only the second woman to win a world sprint treble after leading the United States to 4x100 metres relay gold on Sunday, with Jamaica's Shelly-Ann Fraser-Pryce taking silver in her final race.Jefferson-Wooden had already become the first woman to win a world sprint double since Fraser-Pryce as she dominated the 100m and 200m finals.