Nigeria forward Asisat Oshoala scored early in the second half of her Arsenal debut, after Dominique Janssen had given them an interval lead.
Reading debutant Jade Boho-Sayo pulled one back but Danielle Carter’s header clinched victory for Arsenal.
Oshoala’s charisma is infectious and she told Arsenal fans to expect more as she gets used to life as a Gunner.
She said: “I had fun tonight. It was a very good start for me as an individual, getting to know my players, getting to know a new role.
“I think it was a very good thing for me to grow into the game gradually.
“I promise to give my best to the team. I want Arsenal to win a trophy, win every competition, win every game we play in this season.
“I just have to give it my best in the training sessions and in every game give 100 per cent, this is a very competitive team.
“You have to give your best every time, because we have a lot of good players.
“Three points in the first game of the season is very important for us and very difficult as well, because it’s a home game against a new team and you don’t know the way they are going to play.
“It was a very good win for us.”