The 28-year-old, dubbed the "Russian Rocket," thrilled an expectant and noisy crowd at the Sanki Sliding Centre by easing to victory with a combined time of 3.44.49 for his four slides, a winning margin of 0.81 seconds.
Dukurs, pipped to gold by seven hundredths of a second by Canadian Jon Montgomery in Vancouver four years ago when Tretiakov claimed bronze, had to settle for silver again with American Matt Antoine completing the podium.
"To perform at home in an Olympics is easier because everyone's helping and the supporters are all behind you," said Tretiakov.
"At the same time it's a gigantic responsibility. Such a load has fallen from my shoulders, it's such a relief."
Amid wild cheers, blaring horns, flag waving and chants of 'ROSSIYA', the bearded Tretiakov from Krasnoyarsk in Siberia was calmness personified as he set about protecting his first-day lead of just over half a second.
Dukurs, the dominant slider over the past few seasons with five successive World Cup titles to his name, reduced the Russian's lead by the merest fraction on the third slide but world champion Tretiakov kept calm and increased his advantage on the final run.
Tretiakov, whose wife and sister have also competed in skeleton, was the only slider to dip under 56 seconds over the two days of competition, laying a platform for gold with a track record 55.95 to start proceedings.
Antoine denied a second Dukurs brother a podium place as Tomass Dukurs finished fourth, just as he did four years ago.
An even bigger hard luck story belonged to John Daly, however. The American, 17th at the 2010 Olympics, started his final run in fourth place but blew his medal chances when he made a complete hash of the start with his sled popping out of the track's grooves at the top of the run.
"I knew I had to go for it," he lamented after finishing 15th. "So I went for it and it bit me...the blame is totally on me.
"I really just wish I had one more shot at that last run. Now I have to wait four more years."
- Sports & Recreation