RIO DE JANEIRO, Aug 19 (Reuters) - Usain Bolt secured a sweep of the three men's sprint titles for a third successive Olympics when Jamaica successfully defended their 4x100 metres relay title in 37.27 seconds on Friday. Bolt ran the anchor leg to add the Rio relay crown to the 100 metres and 200 metres titles he had already won for a third straight Games. His ninth gold medal drew him level with Paavo Nurmi, the Finn who dominated distance running in the early 20th century, and American sprinter and long jumper Carl Lewis as the most successful Olympic track and field athletes. ... More...