Hamilton recorded his ninth win of the season in Sochi as Nico Rosberg suffered a pedal problem that ended his race – and with it any realistic chance of the German dethroning his Mercedes team-mate.
Reigning champion Hamilton will secure the title with three races to spare in the United States later this month if he claims two more points than Rosberg and nine more than Ferrari’s Sebastian Vettel.
The Stevenage racer, 30, has now won 43 grands prix, behind only multiple champions Alain Prost and Michael Schumacher, although his only focus is on becoming the 10th man to land a third drivers’ crown.
“The goal is to win a third title. Until I achieve that there is no other goal,” said Hamilton.
“I’ve never felt it’s ever been done and dusted. There are still a lot of points available. I’m going to take my time and, at the next race, work as hard as ever.
"I love going to Austin and the track has been amazing for me since the first race. I am looking forward to it. It’s a track you can race on and get close to people.”
Vettel took second ahead of Force India’s Sergio Perez, who benefited from a last-lap collision between Ferrari’s Kimi Raikkonen and fellow Finn Valtteri Bottas of Williams.
Hamilton may have to wait until the US Grand Prix in Texas on 25 October to add to his 2014 and 2008 titles, but results yesterday confirmed Mercedes as consecutive constructors’ champions.
They too looked short of their target but a 30-second post-race penalty for running into Bottas saw Raikkonen demoted from fifth to eighth place and ended Ferrari hopes of topping the table.
Rosberg started on pole and kept Hamilton at bay for six laps, until his accelerator jammed and he quickly lost places to the Englishman, Bottas, Vettel and Raikkonen.
Hamilton admitted that a rear wing issue that left him unable to use DRS in the closing stages, allied to Rosberg’s enforced retirement, left him anxious about the remaining four races.
“Reliability is something we have focused on a huge amount and for whatever reason, we are having a few problems with it,” he added. “We’ll be working as hard as we can to rectify it, but of course it is a concern for us.”
Rosberg refused to give up on his title chances but struck a demoralised tone after slipping behind Vettel in the standings.
“It’s unbelievable something like this had to happen,” he said. “But I never write anything off, and picking myself up is not a problem either.”