The Gunners midfielder was late when sliding in on Newcastle star Sean Longstaff after 36 minutes of play at St. James' Park.
It sparked an angry response from a number of Magpies players and tensions between the two sides began to boil over as a result.
Havertz escaped with only a yellow card and therefore remained on the pitch for Arsenal, having launched into the aggressive tackle on Longstaff but only catching him with his trailing leg.
But Gabby Agbonlahor believes he's a lucky man.
Speaking on the GameDay Phone-In for talkSPORT, he said: "That tackle by Havertz was like one you used to see in the 1960s, 70s, 80s, it's a Graeme Souness sort of tackle, the sort of tackles Diego Maradona used to get.
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"How has he got away with a yellow card? He's absolutely smashed him! He caught Longstaff, he caught him well enough. Those tackles don't happen anymore."
Amid the feistiness, Newcastle saw three of their players booked as they protested to referee Stuart Attwell.
Anthony Gordon, Fabian Schar and even Longstaff, who was on the receiving end of the tackle, all went into the book for dissent.
There was more animosity towards the end of the first-half as Arsenal believe Bruno Guimaraes should have been punished for an apparent elbow on Jorginho.
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Both sides had time to calm down during the break and emerge for the second half in search of the opening goal.
It was Newcastle who scored but not without any further drama, with Anthony Gordon's close-range finish a controversial one.
VAR checked if the ball had gone out of the play in the build-up and if Joelinton was adjudged to have fouled Gabriel.
The officials also suspected a potential offside but after a long wait, the goal was given and Newcastle went on to claim a huge win.