RIO DE JANEIRO (AFP) - Britain's Mo Farah became the first man since Finland's Lasse Viren in 1976 to retain two Olympic distance titles when he won the 5,000m on Saturday.

After retaining the 10,000m title last week, Farah produced an exemplary race to win a second 5,000m gold in 13min 03.30sec.

Ethiopian Hagos Gebrehiwet took silver in 13:04.35 while Kenyan-born American veteran Bernard Lagat claimed bronze (13:06.78).

Another Kenyan-born American, Paul Chelimo, was initially awarded silver before being disqualified.

Dejen Gebremeksel, silver medallist behind Farah in London four years ago, and Gebrhiwet set out on a fast pace, Farah sat at the end of the strung-out field at the Olympic Stadium in perfect conditions.

Chelimo, one of three foreign-born Americans in the field along with the 41-year-old Lagat and Somali-born Hassan Mead, was happy tagging along in third as Farah moved up to sixth.

The Ethiopians alternated the lead, with Kenyan-born Bahraini Albert Rop also in the mix.

With five laps to run, Farah was well positioned in second and then took over the lead, immediately dropping the pace so the pack bunched back up.

Farah led the 15-strong field through the 4,000m mark in 10:39.4 as the pace again picked up for the final kilometre under pressure from Ugandan Joshua Cheptegei.

Farah went through the bell head-to-head with Gebrewihet, who punched down the back straight. But Farah held firm and surged again from 200m.

Chelimo looked like he might have had the beating of the Somali-born Briton as they entered the home stretch, but Farah found an extra step in his stride, timing 52.83sec for the final lap for a famous win.

The victory sealed a distance double last achieved when Viren triumphed in the 1972 and 1976 Games in Munich and Montreal.

In a stellar career, Farah has already achieved the world double-double at the 2015 and 2013 championships in Beijing and Moscow.