Here are five things we learned from the game.
1. Alex Iwobi Has Been the Forgotten Man During Arsenal's Striker Woes
Arsenal fans were worried about the club's options up front when news broke that their signings in that area of the pitch consisted of Takuma Asano and Lucas Perez.
But not enough has been said about promising youngster Alex Iwobi, who was electric at the KCOM. He looked red-hot around the penalty area and brought the likes of Walcott and Sanchez into play with some incisive passes. His back heel to set up Walcott was phenomenal.
What were they worrying about?
2. Hull Are Over-Reliant on Abel Hernandez's Performances
Abel Hernandez has been lethal in the past year for Hull, scoring buckets of goals in their promotion success. However, a tight Arsenal defence marked him out of the game and Robert Snodgrass failed to compensate for the loss with a disappointing game, despite a well-taken penalty.
That left the task of supporting Hernandez to Adama Diomande, who only excelled in build-up play and soon faded himself. A miserable day for Hull, which you felt was down to Hernandez being kept quiet.
With goals in short supply, bear in mind that Hull's only goal against Burnley last Saturday also came from a late set-piece.
3. Arsenal's Centre-Back Concerns Are Buried for Good
Another worry for Arsenal fans was the centre-back position, which was exploited by Liverpool in their 4-3 victory in the opening game of the season. Rob Holding and Calum Chambers were exposed.
Since then, Wenger has brought in Shkodran Mustafi, and Laurent Koscielny is fully fit again. Both were impressive today, especially the former. Apart from one dodgy challenge for which he could have been booked, Mustafi was a rock. Koscielny had less to do, but was confident in everything he did.
From being shaky and worrisome, the centre-back positions have become an area of strength for Arsenal.
4. Hull Are Not the Next Leicester City
Hull have won credit with the pundits so far this season for their heroic efforts in defending after downing Leicester themselves and fighting until the last against Manchester United. Here, though, they unravelled.
Forget the fact that Livermore was sent off; Arsenal were well in control anyway. Hull were undone over and over again and easily put away.
5. Arsenal Can Be Title Contenders After All
Arsenal are one of six names being put forward as title winners this year, but they only scraped a win against Southampton at the Emirates and could easily have been beaten by Leicester to go alongside the Liverpool fiasco.
If they can maintain this type of play in the coming weeks however, they might be taken more seriously. Manchester City look irrepressible currently, but Wenger's men can keep themselves in and around the title picture if they can replicate the efforts shown today.