The Blues were able to score one goal for the Belgian national and take home three points at Stamford Bridge.
Lukaku signaled to his teammate with his left hand that he wanted the ball. Cesar Azpilicueta sent in a beautiful lofted cross from just outside the penalty box. He scored a goal just inside the near post at the 69th minute.
Sergei Semak's men were able to hold their own at this point in the contest. They not only protected well, but also created opportunities for attack.
Chelsea was unable to penetrate their opponent's four defenders, five midfielders and five midfielders despite their offensive power.
Lukaku was able to play well while keeping his back to Zenit's goal, but that wasn't enough to cause any danger in the last third.
In the meantime, the Russian team visited Iran to try to exploit the speed of Sardar Azmoun, an Iranian forward, and was able to score the first goal in the 38th minute of a generally disappointing first half.
Zenit Saint Petersburg was close to equalizing after Lukaku's goal. Substitute Artem Dzyuba received Azmoun's cross, but his attempt was just too wide.
After the match, Thomas Tuchel, Chelsea's head coach, said that "we struggled to create chances and shots" in the first half. He was speaking after the match in front of almost 40,000 people. It was easier to find space to shoot in the second half. It was well deserved. It was hard earned."
After Chelsea paid a club record 97.5 million pounds ($135million) to purchase him from Inter Milan, Lukaku is now back at Stamford Bridge.
Chelsea's win places them in second place in GroupH behind Juventus. They defeated Malmo 3-0 on Tuesday. Chelsea also have the advantage in goal differential.
Semak stated that his players allowed Chelsea to play more than they should after the interval.
Zenit manager stated that they had a great opportunity at the end but didn't seize it. It's still a fair result. Chelsea was the better team, and they deserved to win. We had a good game overall, especially defensively." EFE