Andrey Moiseev became the first man for 52 years to win back-to-back gold medals in the men's Olympic modern pentathlon.
The Russian finished ahead of the Lithuanian duo of Edvinas Krungolcas and Andrejus Zadneprovskis, a double world champion and a silver medallist in Athens four years ago, having led into the concluding 3,000 metres run.
Moiseev's final total in the demanding one-day event saw him finish with 5,632 points with Krungolcas on 5,548 and Zadneprovskis 5,524.
China's Qian Zhenhua, second heading into the concluding 3,000 metres, faded in front of his home crowd and finished out of the medals in fourth after collapsing over the line.
Moiseev was 52 points ahead of Qian after the show-jumping, the fourth event of a competition also featuring target shooting, fencing, and swimming.
Under the system used to ensure the first home in the 3,000 metres is also the overall winner, that gave Moiseev a 13 second head start over Qian.
The 3,000m was, unusually, not held on a cross-country course but over an athletics track at the Olympic Sports Centre (OSC) Stadium where the runners were made to take several turns in what were effectively three laps of 1,000 metres each.
Michal Michalik's victory in the penultimate showjumping phase saw him go up to fifth place. But fellow Czech David Svoboda, who had been third, dropped down the field to 31st.
The showjumping saw five of the 36-man field fail to finish the 12 obstacle course, situated inside the confines of the OSC athletics track.
No-one managed a clear, with Michalik's 28 penalties in a time of 69.37 seconds the best effort.
There were numerous refusals, several falls and repeated instances of horses ploughing through a fence in a competition which, unlike other equestrian events, sees competitors on mounts they've never previously ridden.
There had been complaints in the build-up about the quality of horses being used in Beijing.
But the wet conditions underfoot did not help and experienced observers said some of the most dramatic falls were as much the result of bad riding as anything else.
The worst case saw John Zakrzewski flipped over, dragged along when his foot still in the stirrups and stamped on by his mount to leave the Frenchman with a bloodied face.
Svoboda had earlier scored 191 out of a maximum 200 in the 10-metre pistol shooting, surpassing the previous Olympic best of 186 shared by the Belarus duo of Pavel Dougal (Sydney 2000) and Dmitry Meliakh (Athens 2004).
But no man who has won the shooting has gone on to take the modern pentathlon gold medal.
In the epee fencing both Moiseev and Qian won 26 of their 35 bouts.
Egypt's Amro el Geziry set a new Olympic modern pentathlon 200 metres swimming record of one minute 55.86 seconds, breaking Moiseev's mark in Athens four years ago of 1:58:88.
But he gave away a massive 716 points in the showjumping, where all riders start with 1200 points but then suffer deductions for having fences down, refusals and a failure to complete the course in the allotted 75 seconds.
Lars Hall of Sweden in 1952 and 1956, the first non military winner of the title, was the last man to win back-to-back Olympic modern pentathlons.