RIO DE JANEIRO - Kenya's David Rudisha cemented his status as the best middle-distance runner ever by retaining his 800m Olympic title.

The 27-year-old crossed the finish line at the Olympic Stadium in 1min 42.15sec on Monday, 0.46 ahead of silver medallist Taoufik Makhloufi of Algeria.

American Clayton Murphy clocked 1:42.93 in the two-lap race to complete the podium.

Rudisha is just the fourth man to win this event twice at the Olympics. He joins Great Britain's Douglas Lowe (1924-1928), American Mal Whitfield (1948-1952) and New Zealand's Peter Snell (1960-1964) in achieving the feat.

Four years ago in London, Rudisha - nicknamed "King David" - won gold in a world record time of 1:40.91.

"Running 1:42, it's just fantastic. I had no doubts before," he said. "The feeling in my body was good. It is great to win such a big competition, my second gold. It's so great. I am so excited. It is the greatest moment of my career."

The double world champion owns the three fastest times in history.