The Gunners returned to winning ways after defeating Crystal Palace 5-0 at the Emirates on Saturday.
Arsenal got its first league win in the New Year starting with an 11th-minute header by Brazilian defender Gabriel.
He pounced a powerful nod past Henderson after a corner kick from Declan Rice came flying in.
Henderson had an own goal to his name after the ball hit the back of his head, a goal Palace players felt was caused by an obstruction from Ben White.
Thanks to a counterattack launched by Arsenal goalkeeper, Raya, who quickly threw the ball into the path of Gabriel Jesus.
The Brazilian paced the ball before laying it to Belgian teammate, Trossard, who fired the ball past Henderson.
Not quite a team ready to hang on to the 3-0 lead, the Gunners continued to show their attacking prowess towards the end of the game.
Martinelli registered two instant goals in stoppage time to earn the Gunners a comfortable victory against Roy Hodgson’s side.
Arsenal had lost their last two EPL matches in 2023 in a 2-0 home loss against West Ham before falling to a 2-1 defeat by Fulham at Craven Cottage, followed by a 2-0 FA Cup loss against Liverpool.
With the win on Saturday, Arsenal stay in the third position, the same point as Manchester City and two points behind table leaders Liverpool.
Palace stay five points above the relegation zone with 21 points.
