The much-maligned summer signing from Chelsea stooped to head in from a curling Bukayo Saka cross to the far post.

The visiting Arsenal supporters could not believe their luck as they celebrated long and hard on a freezing west London night.

Mikel Arteta’s side had been gifted an opportunity to leapfrog their rivals after Manchester City dropped points at home to Liverpool earlier in the day, but failed miserably for the most part.

They showed no sign of having the ability to take advantage of their chance against a Brentford side happy to defend and wait for a chance on the break.

Havertz was NO.1 name on the lips of the Gunners supporters, closely followed by keeper Aaron Ramsdale – back in the starting line-up as Brentford loan signing was not allowed to play against his parent club.

It nearly went so wrong for last season’s first-choice Arsenal keeper as Raya watched on from the sideline.

Twice his errors nearly led to Brentford goals and he was lucky to escape with a clean sheet.

‘You’re just a sh1t David Raya’ chanted the Brentford faithful. The Spanish keeper, in view of many in this small well-lit stadium, sat with a blank expression in a seat tucked in just behind the Arsenal dugout.

"Whooooooaaaaaah!" roared the home fans every time the ball went anywhere near Ramsdale from then on. A real test of character for the young English keeper fighting to prove he has a future at the club under Arteta’s leadership.

Hard to say if it unsettled the rest of the Arsenal players too, but they struggled to make an impact on the match and Brentford held them comfortably.

The fickle fate of football played another cruel trick on Arsenal soon after when it seemed a goalkeeping error by Raya’s Brentford replacement Mark Flekken had put them ahead. He weakly palmed a Jesus header to where Trossard was well placed to head in. One of those long VAR delays ensued before the Belgian was ruled offside by the width of a shoelace.

A match low on quality and incident then played out with neither side looking like they had the guile or guts to go for the jugular.

Oleksandr Zinchenko came up with Arsenal’s second memorable goal-line clearance of the night with just over ten minutes to go as he denied Brentford sub Neal Maupay an unlikely winner and set up a slightly tense finish.

Then came Havertz and his dramatic winner just when it was least expected.

"It feels amazing," the matchwinner told BT Sport. "I've been working hard for this moment. It was a brilliant pass. We train this routine quite a lot. It was a good goal.

"Football is always hard work. Nothing comes from itself. You have to work and keep belief. It was tough for me the last couple of months, but I try to put my ego aside too because the team is the most important thing.

The Arsenal fans serenaded Havertz loudly in the closing minutes and the German was appreciative of the backing he has received despite not hitting the ground running. 

"I've been thankful for these guys. I know it's always hard when a new signing comes and they pay a lot of money for you, Sometimes they think it will come quite easy and quite fast. "

BRENTFORD: Flekken 5, Pinnock 6, Norgaard 6, Wissa 6 (Maupay 72), Mee 6, Ajer 6, Yarmoliuk 6 (Baptiste 72), Onyeka 6 (Lewis-Potter 90), Ghoddos 7 (Zanka 90), Mbeumo 6, Janelt 6. Subs: Strakoshka, Goode, Peart-Harris, Olakigbe, Brierley.

ARSENAL: Ramsdale 5, Tomiyasu 6, Saliba 6, Gabriel 6, Zinchenko 7, Rice 6, Odegaard 7 (Jorginho 90), Saka 6 (White 90), Trossard 6, Martinelli 6 (Havertz79) , Jesus 6 (Nketiah 65). Subs: Hein, Kiwior, Soares, Nelson, Elneny 

Ref: Tim Robinson 4