Arsenal inflicted a first Women’s Super League defeat on Manchester City, who conceded for the first time in 2019-20.
Vivianne Miedema and Lisa Evans had chances for the hosts early on, while Beth Mead was close to getting on the end of Kim Little’s cross.
Miedema put Arsenal ahead just before half-time as she finished neatly from Little’s delicate through ball.
The visitors offered little throughout, although their best chance came from Janine Beckie’s long-range shot.
Arsenal, who have now won 15 of their past 16 homes games, were always a danger as Evans hit the bar in the second half and Jordan Nobbs put a volley just wide.
The home side missed a glorious chance for a second in injury time as Nobbs dragged her shot wide of the left-hand post from the edge of the box after good work by Miedema on the left wing.