The Group B fixture had appeared in doubt when the other match in the group between Denmark and Finland – taking place two hours earlier – was suspended after Eriksen collapsed in the first half.
A lengthy delay occurred but after the Inter playmaker was able to regain consciousness and was taken to hospital, where he is in a stable position, the first match in the group resumed and Belgium were able to take on Russia, which ended in a routine victory for Roberto Martinez's men.
Semi-finalists at the World Cup in Russia three years ago, Belgium went top of the group thanks to a brace by Lukaku that sandwiched Thomas Meunier's goal.
Eden Hazard was left on the bench in St Petersburg and there was an unsavoury start when the Belgium players were booed as they took the knee before kick-off.
Lukaku was able to respond in the perfect fashion after 10 minutes when he put the number one ranked team in the world ahead.
Dries Mertens' cross was not dealt with by Andrey Semenov and former Everton and Manchester United striker Lukaku fired the ball in with his left foot before he grabbed the pitchside camera saying, "Chris, I love you" in a message to team-mate Eriksen.
Russia came out with more intent after the interval but despite using all five of their substitutions by the 63rd minute, including taking off Kuzyaev's replacement Denis Cheryshev, Thibaut Courtois remained largely untroubled in the Belgian goal.
Captain Eden Hazard was able to play the final 18 minutes and there was time for the goalscorers to combine for a third.
Meunier played Lukaku through on goal and he drilled the ball low into the corner for his second of the night to ensure one of the favourites started on a positive note.