London (AFP) - Chelsea showed they can thrive without Romelu Lukaku as Kai Havertz scored after replacing the axed Belgium striker for the 2-0 Champions League last-16, first-leg win against Lille on Tuesday.
Thomas Tuchel's side took control of the tie thanks to Havertz's first-half header and Christian Pulisic's clinical finish after the break at Stamford Bridge.
The holders will expect to complete their progress to the quarter-finals when they travel to France for the second leg on March 16.
But Chelsea's sixth successive win in all competitions was more a referendum on their Lukaku conundrum than an indication of their chances of retaining the trophy.
Lukaku has scored just 10 goals since a club record £97 million ($131 million) move from Inter Milan last year that was expected to launch a period of sustained dominance for Chelsea.
He touched the ball only seven times in Saturday's 1-0 win at Crystal Palace, the lowest total by a Premier League player since 2003-04.
Despite being infuriated in December by Lukaku's public questioning of the way he was being used, Tuchel had appeared to back him on Monday, insisting his problems were no laughing matter.
But, tellingly, Chelsea were more potent in Lukaku's absence and it remains to be seen if Tuchel will trust his beleaguered star in the League Cup final against Liverpool on Sunday.
At least Tuchel knows Chelsea have the ammunition to damage opponents while their supposed leading man labours.
"For Kai, I'm very pleased.He's been very strong for several weeks now.He really stepped up.The work rate is immense.The areas of the pitch he covers for us is very good.He is never shy of defending," Tuchel said.
"Romelu struggled in the last game to deliver.Not only mentally tired, but physically, which I can understand.It was the moment to take a step back.
"Today we went with other players.For Sunday we have four days to recover and decide who plays."
Chelsea's Ben Chilwell, Reece James and Callum Hudson-Odoi paraded the Club World Cup around the pitch just before kick-off.
However, that victory in Abu Dhabi will be only a footnote in the story of Chelsea's season if they don't mount a strong finish to an inconsistent campaign.
This was a step in the right direction and Havertz didn't take long to get involved.
Forceful Havertz
Cesar Azpilicueta's low cross was begging to be finished off, but the German forward poked his effort over the bar from six yards.
If that was a concern for Tuchel, he would have been relieved that Havertz looked more threatening as he cut inside for a fierce strike which Leo Jardim pushed away at full stretch.
From the resulting corner, Havertz gave Chelsea an eighth-minute lead.
Taking advantage of Lille's woeful marking, Havertz met Hakim Ziyech's corner with a downward header that bounced in for his seventh goal this season.
Havertz, more forceful and energetic than Lukaku on current form, needed just 15 minutes to record more touches than the Belgian managed in the entire Palace game.
After an initial bout of stage-fright, the French champions probed intelligently for openings, with Benjamin Andre's long-range drive held by Edouard Mendy.
Tuchel's agitated body language betrayed his frustration at Chelsea's failure to build on their lead in the first half.
However, he got his message across and there was more urgency about Chelsea after the interval.
Marcos Alonso's goalbound drive was diverted to safety by Zeki Celik before Ziyech and Mateo Kovacic were forced off.
Chelsea weren't hindered by the injuries and doubled their lead with a sweeping counter-attack in the 63rd minute.
Thiago Silva started the incisive raid with a superb pass to N'Golo Kante, who advanced at speed towards the Lille area before slipping a pass to Pulisic.
Taking two touches, Pulisic steadied himself and clipped a composed finish past Jardim from 10 yards.
