It was a night to remember for Mo Farah, who achieved the "double-double" at Rio 2016 by adding 5000m gold to his 10,000m victory.
Mo Farah confirmed his standing among the distance-running greats by claiming a superb victory in the men's 5000 metres to complete a famous 'double-double' at Rio 2016.
The Briton repeated his feat of winning the 5000m and 10,000m at London 2012 four years ago, becoming the first man since Lasse Viren in 1972 and 1976 to do so.
Farah put in a typically astute performance before producing a trademark strong finish to hold off a late charge from Paul Chelimo and take victory in a time of 13 minutes and 3.30 seconds.
Chelimo was one of three men subsequently disqualified, along with Canada's Mohammed Ahmed and Ethiopia's Muktar Edris, which ensured Hagos Gebrhiwet was promoted to second and 41-year-old Bernard Lagat took bronze, sixteen years after claiming his first Olympic medal in the 1500m at Sydney 2000.
Farah had to recover from a fall to win his 10,000m title and also stumbled in the heats of the shorter distance in qualifying for the final.
It was a more straightforward victory on this occasion, though, with Farah again judging the timing of his attack to perfection.
The Ethiopian trio of Edris, Gebrhiwet and Dejen Gebremeskel - silver medallist four years ago - set a fast pace in the early stages in a bid to unsettle Farah.
But it was a pace that could not be sustained as Farah soon positioned himself at the head of the field and by the time the 33-year-old took the bell there was a sense of inevitability about the outcome.
Chelimo briefly threatened an upset, but Farah once more proved too strong on the home straight, securing his fourth Olympic gold.
There was disappointment to follow for Chelimo, who would have been the first American since 1964 to take silver in the 5000m, as he was stripped of the silver medal.