Despite Jackson signing a contract extension earlier in September that will keep the Senegal star at Stamford Bridge until 2033, there were demands for Nkunku to be given a starting role after the French forward scored coming off the bench in the 1-0 win at Bournemouth.
Jackson scored 17 goals in an inconsistent debut season with the Blues and was guilty of missing a number of big chances.
But the 23-year-old has been in fine form at the start of this season and already has four goals in six games in all competitions.
Chelsea have won all three away league games this season, losing only once, against champions Manchester City, in their five top-flight matches.
Despite a reported power struggle between Chelsea co-owners Todd Boehly and Behdad Eghbali behind the scenes, former Leicester boss Maresca, who replaced Mauricio Pochettino in the close-season, has made a strong first impression.
After disappointing sixth and 12th place finishes in the last two seasons, there are encouraging signs that the Italian could be the manager to turn Chelsea's expensively assembled squad of underachievers into top four contenders.
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The Hammers' dismal start to the season has already put new boss Julen Lopetegui under pressure, with the former Spain and Real Madrid boss jeered by the few frustrated fans who hadn't fled the ground well before the final whistle.
West Ham have won just one of their five Premier League games this term, losing three in a row at home to start a league campaign for the first time.
- Rampant Chelsea -
Chelsea made a flying start after just four minutes when West Ham switched off at a free-kick, allowed Jackson to take Jadon Sancho's pass and surge down the right flank.
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Jackson cut into the penalty area and beat Alphonse Areola's weak attempted save with ease.
It was Chelsea's earliest goal in a Premier League London derby since Daniel Sturridge netted against QPR in 2012.
Jackson was proving impossible for West Ham to subdue and he teed up Cole Palmer for a low strike that flashed just wide.
Chelsea's pressure was relentless and there was a sense of inevitability about their second goal in the 18th minute.
At the climax of a free-flowing move, Moises Caicedo produced a deft pass that pierced the West Ham defence, allowing Jackson to guide a composed finished past Areola.
Jarrod Bowen summed up West Ham's sluggish start with a woeful shot that ballooned over from a good position.
Making his first league start for West Ham after his close-season move from Leeds, Crysencio Summerville demanded a penalty after Wesley Fofana's tug sent him sprawling, but VAR rejected the forward's appeals.
Lopetegui was furious with West Ham's lethargy and responded by hauling off Argentina midfielder Guido Rodriguez before half-time.
But Rodriguez's replacement Thomas Soucek hardy improved Lopetegui's mood when he wastefully fired straight at Chelsea keeper Robert Sanchez.
Sancho looked revitalised following his loan from Manchester United, causing problems with his nimble dribbling in his first Premier League start since May 2023.
Palmer killed off West Ham in the 47th minute as the England forward took Jackson's pass and slotted past Areola from a tight angle.
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(Except for the headline, this story has not been edited by staff and is published from a syndicated feed.)