The striker started and finished a sublime Blues move in the 15th minute, turning home Reece James’s centre after bullying the Gunners defence to create the space for himself.

Chelsea continued to menace, James in particular a constant threat down our right, and it was who doubled our lead shortly after the half-hour, controlling a Mason Mount pass and emphatically firing past Bernd Leno.

In response Arsenal occasionally threatened after the break. Edouard Mendy saved from Bukayo Saka and Cesar Azpilicueta brilliantly thwarted Emile Smith Rowe, while Rob Holding missed their best chance with a header from six yards out.

In truth, though, a comeback never looked likely as the Blues largely kept our hosts at arm’s length, and with a little more final-third precision we would have added to our two first-half goals. Lukaku came closest, seeing a header somehow tipped on to the bar by Leno.

Still, the Belgian’s second Chelsea debut was one to remember, with a goal and three points against a local rival to the backdrop of the travelling faithful chanting his name at regular intervals.

London is blue tonight!

The selection

Lukaku was one of three changes Thomas Tuchel made to his starting line-up, with Kai Havertz and James handed their first league starts of the campaign. Timo Werner, Trevoh Chalobah and the isolating Christian Pulisic made way.

N’Golo Kante and Hakim Ziyech were back on the bench after injury, with both introduced in the second half.

For our hosts, Saka started having come off the bench at Brentford. Pablo Mari and Cedric Soares were brought into the defence with Ben White unavailable.

Sharp start

It was Saka who created the first opening with 60 seconds on the clock, nodding the ball into Smith Rowe’s path on the edge of the box. His shot was on target but comfortable for Mendy.

Straight down the other end Chelsea went. Marcos Alonso invited James to chance his arm from 20 yards, and it needed a block from Granit Xhaka with his face to stop the sweetly-struck shot that followed testing Leno.

The tempo and physicality remained high in the north London sunshine, but the moment the Blues started to dominate possession, we took the lead.

Back with a bang!

It was a wonderfully crafted goal, too, with Lukaku showcasing everything he has to offer this team in the blink of an eye. Mateo Kovacic fed him on the edge of the box, back to goal, occupying Arsenal’s central defenders. He laid the ball back to Kovacic, who picked out the unmarked James with an incisive lofted pass to his right.

Meanwhile Lukaku had comfortably brushed off Mari and burst into the six-yard box, where he couldn’t miss James’s inviting centre. Immediately the away end serenaded their new man!

The strength of Lukaku allowed Mount to nearly play in Havertz as we sought a quick second, and then Mount had a shot blocked after an exquisite Havertz pass freed James once more.

The tussle between Lukaku and Mari continued with the latter managing to get a block in as our no.9 threatened on his right. Shortly after the half-hour, the defender was booked for scything Lukaku down on halfway. It is safe to say he did not enjoy his afternoon.

Double trouble

Then came number two! This time much of the credit must go to Alonso and Havertz down our left, who engineered space where there was none. Alonso’s pass infield reached Mount who quickly shifted it on to James, again with the freedom of the Emirates to enjoy. This time he went for goal himself and how, thumping a finish high into Leno’s top corner.

We weren’t content to sit on our two-goal advantage, and Havertz wasn’t a million miles away from glancing Mount’s cross in following superb speed and skill from the England midfielder.

Save for a penalty appeal waved away after James and Saka came together, we saw the remainder of the half out with relative ease, the teeming rain and gloomy skies reflecting the mood of the vast majority of those inside the Emirates.

Lukaku nearly bulldozed an opening for himself when play restarted, eventually crowded out, and Mendy was called into serious action for the first time since the opening minute, tipping a deflected long-range Saka strike over.

Arsenal continued to try and inject some impetus into their attacking play, and they were nearly rewarded on the hour. We had conceded a goal from a corner here in pre-season, and lightening nearly struck twice when Mari nodded the first header across goal, only for Holding to contrive to plant his header wide.

Mikel Arteta then brought Pierre-Emerick Aubameyang on for Saka, and the Gabonese forward beat our offside trap only to be thwarted by the alert Mendy, who raced off his line and cleared. Nuno Tavares for the injured Kieran Tierney was the next sub, before Kante came on to huge cheers from a joyous away end. Kovacic made way.

Before then, a magnificent block from the ever-dependable Cesar Azpilicueta stopped Smith Rowe halving the deficit from close range.

There was some concern for James who feel to ground in some pain holding his neck. Thankfully, he was okay to continue.

Lukaku so nearly had his second and our third with a quarter-of-an-hour remaining, only to be denied by a stunning point-blank Leno save, which tipped his header from Mount’s cross onto the crosser. Big Rom couldn’t believe it!

Havertz had a couple of late opportunities to finish things once and for all but found his compatriot Leno in his way. So we settled for two goals and three very satisfying points indeed.

What’s next?

It’s Liverpool away on Saturday for Thomas Tuchel’s side, that one a 5.30pm kick-off.

Chelsea (4-2-3-1): Mendy; Azpilicueta (c), Christensen, Rudiger; James, Jorginho, Kovacic (Kante 72), Alonso; Mount (Ziyech 82), Lukaku, Havertz (Werner 90)Unused subs Kepa, Chilwell, Chalobah, Thiago Silva, Zouma, Hudson-OdoiScorers Lukaku 15, James 35

Arsenal (4-2-3-1): Leno; Soares, Holding, Mari, Tierney (Tavares 66); Lokonga, Xhaka (c); Pepe, Smith Rowe, Saka (Aubameyang 61); Martinelli (Balogun 79)Unused subs Ramsdale, Chambers, Kolasinac, Tavares, Maitland-Niles, Elneny, Nelson.Booked Mari 34, Holding 45, Lokonga 67

Referee Paul TierneyCrowd 58,729 (tickets sold)