Chelsea continued their Champions League title defense with a 2–0 win against Lille in their last 16 game at Stamford Bridge.
Kai Havertz's header within the first eight minutes opened the scoring for Chelsea on Tuesday, before Christian Pulisic won the match when he ended a break in the middle of the second half by N'Golo Kante.
The win gives Chelsea a healthy advantage ahead of the second leg at Lille on 16 March.
"I think we didn't play our best football, it was tough," Havertz told BT Sport. "I think, we couldn't find the aggression on the pitch, which we used to have in the last few weeks."
Before his goal, Havertz had two chances to give Chelsea an early lead, first when he tried to convert a cross from Cesar Azpilicueta, then again when he faced a saved shot by Lille goalkeeper Leo Jardim.
The German international, who won last year's Champions League final against Manchester City, finally found his goal moments later when he overtook Jardim from Hakim Ziyech's corner.
Lille, the defending champions in France's Ligue Un, but currently eleventh in the table, settled in the game after a goal from Havertz, but failed to deliver a clear goal-scoring chance in the first half.
Chelsea continued to control the game in the second half as well. The Blues doubled their lead just after the hour mark, when Kante swung the ball toward Lillee's box and passed to Pulisic, who stuck the ball into the back of the net.
After winning the Club World Cup earlier this month, Chelsea now have a chance to win more silver in this weekend's EFL Cup final against Liverpool.
In Tuesday's second game, Villarreal and Juventus drew 1-1 for the Spanish side after Dani Parejo equalized in the second half. Dusan Vlahovic then made his Champions League debut with just 33 seconds into the match to give Juventus the lead. The teams meet again on March 16 to determine who advances to the quarter-finals.