Beijing: Usain Bolt secured a sweep of the sprint gold medals at a World Championships for the third time on Saturday when, aided by a US disqualification, he anchored Jamaica to the 4x100 metres relay title.

The 29-year-old, who had already won the 100 and 200 metres events at the Bird's Nest Stadium, stormed across the line in 37.36 seconds to give his country a fourth straight world title in the event.

The US team, featuring Justin Gatlin, who won silver behind Bolt in both individual sprints, botched their final handover between Tyson Gay and Mike Rodgers and were disqualified after crossing the line second. That elevated hosts China to a hugely popular silver medal in 38.01 with Canada taking the bronze in 38.13.

It was a record-extending 11th world gold for Bolt, who also won three sprint titles at the 2009 and 2013 world championships. His teammates Nesta Carter, Asafa Powell and Nickel Ashmeade helped extend Jamaica's dominance of the sprint relay to a sixth straight major global championships, including the last two Olympics.

Jamaica's women's team, anchored by Shelly-Ann Fraser-Pryce, clocked the second fastest time in history to retain their 4x100 metres relay title, at the World Championships on Saturday. Veronica Campbell-Brown, Natasha Morrison and 200 metres silver medallist Elaine Thompson ensured Fraser-Pryce had a good lead when she took the baton and the 100 metres champion stormed across the line in 41.07 seconds. The US finished second in 41.68, with Trinidad and Tobago winning the bronze.

Britain's Mo Farah kicked on the final corner and stormed down the home straight to retain his 5,000 metres world title on Saturday, securing an unprecedented third successive distance double at major global championships. The 32-year-old Olympic champion, who won the 10,000m in Beijing last weekend, clocked 13 minutes 50.38 seconds to win a record third straight 5,000 metres world title. It was Farah's seventh successive major distance crown.

Piotr Malachowski of Poland claimed the discus gold with a throw of 67.40 metres. The 32-year-old Pole dominated the event to finally win the world title after landing silver medals in 2009 and 2013 and being Olympic runner-up in the same Bird's Nest Stadium seven years ago.

Mariya Kuchina won the women's high jump with a clearance of 2.01 metres to become Russia's second gold medallist here.

Marina Arzamasova of Belarus outsprinted defending champion Eunice Sum down the home straight to win gold in the women's 800 metres.

Matej Toth became the first Slovakian to win a gold medal at the Worlds when he cruised to victory in the men's 50 km race walk. The 32-year-old Toth surged ahead after opening up an early lead in the gruelling event to win in a time of three hours, 40 minutes and 32 seconds on a hot and humid morning in the Chinese capital. Australia's Jared Tallent finished second. Tallent completed the journey in 3:42:17, with Japan's Takayuki Tanii, last year's Asian Games champion, taking the bronze medal in 3:42:55. (Reuters)