The Brit arrived in Sochi seven points adrift of Vettel after the Ferrari driver claimed victory number two of the new season at the last race in Bahrain.
The Mercedes driver has won two of the three races staged in Russia and will be desperate to make amends following his defeat at the Sakhir Circuit to Vettel a fortnight ago. But it was the German, and his resurgent Ferrari team, who appeared on course to strengthen their grip on the new championship after a dominant display at the Sochi Autodrom.
First, his Ferrari teammate Kimi Raikkonen posted the fastest lap in opening practice before Vettel soared to the top of the timesheets during the day’s second running.
Vettel set a best lap of one minute and 34.120 seconds at this 3.1-mile circuit which runs through the Olympic Park - the site of the 2014 Winter Games - to finish ahead of Raikkonen, while Hamilton was only fourth.
Hamilton was slower, not only to both the Ferrari drivers, but his Mercedes team-mate Valtteri Bottas too as he ended the 90-minute session a distant 0.709 seconds adrift of Vettel’s best time.