For all Chelsea have improved under Thomas Tuchel, finding a consistent source of goals has been a struggle for the new Blues manager.
Mason Mount is the club's top scorer from open play since Tuchel replaced Frank Lampard with three strikes, while Olivier Giroud was the only other player to have netted more than once under the German when not factoring in set-pieces.
It is not as if Tuchel is short of options, with Timo Werner, Christian Pulisic, Tammy Abraham, Hakim Ziyech and Kai Havertz all available to him in attacking areas.
On Monday against Everton it was Havertz's turn to stake his claim, and the Germany international put in the kind of display that suggested he could well be the missing piece for Chelsea's forward line.
Making his first league start since Tuchel's debut game in charge against Wolves, Havertz was deployed in a central role between wide forwards Werner and Callum Hudson-Odoi, playing as a 'false nine'.
It is a position he thrived in during his final weeks at Bayer Leverkusen, scoring eight goals in 11 games for Peter Bosz's side in a run that convinced Chelsea to splash out £70 million ($97m) on the 21-year-old over the summer.
And it has been clear for some time that Tuchel sees it as his best role.
“He is a unique player,” Tuchel said last week while injury held back Havertz's chances to start games.
“It’s not so clear where he needs to settle, does he need to settle on one special position? Or is he kind of a hybrid player. Today, I would say he’s in between a nine and a 10, something in between."
Tuchel stuck to his guns here, and Havertz repaid him with a match-winning performance that provided the Blues' attack with everything other than an actual goal.
Havertz would be forgiven for feeling hard done by on that account given it was his shot that Ben Godfrey deflected into his own net during what was otherwise a tight first half between two top-four challengers.
If it was the statisticians that stopped Havertz getting on the scoresheet before the break, then it was the officials in the second period, as his close-range volley was ruled out for handball in the build-up by the playmaker.
His influence continued to be felt, however, and it was Havertz who won the penalty which sealed all three points for Tuchel's side as he showed good pace and movement to get in behind and force Jordan Pickford into a foul.
Jorginho converted from the spot, but this game was all about Havertz and the impact he could have on this side going forward as he combined well with both Werner and Hudson-Odoi.
Under Lampard he found himself playing in a variety of positions, though he most commonly featured as a number eight in a three-man midfield.
That is a role which requires defensive discipline as well as attacking awareness, but Havertz is far more comfortable operating solely in the final third, and in central areas rather than out wide.
"He’s very comfortable in the box. He’s very comfortable in high positions. He’s very good at offensive headers, has good timing to arrive in the box, good finishing and good composure in the box," Tuchel said last week, and most of those attributes were on show against Carlo Ancelotti's side.
It may only have been one game, but the signs are that Havertz has found a home in the Chelsea side. Tuchel's jigsaw could be close to completion.