Pierre-Emerick Aubameyang's hat-trick helped Arsenal to a welcome first win of the season as they beat a young West Bromwich Albion side to reach the Carabao Cup third round.
Aubameyang marked his first start of the season with two first-half tap-ins and a curling finish after the break.
He also acrobatically set up Nicolas Pepe for the third, with Bukayo Saka slotting in the Gunners' fourth.
Alexandre Lacazette came off the bench to fire in his side's sixth.
The win could have been even bigger too, with Martin Odegaard hitting the outside of the post from a tight angle and Pepe striking the bar with a chip.