Frida Maanum scored an early opener before Mead doubled the Arsenal lead with a brilliant curling finish and soon added her second from close range.
Mead was making her second successive start following 11 months out due to the serious knee injury that caused her to miss the World Cup.
She becomes the second player to reach 100 goal WSL contributions (57 goals, 43 assists), after Vivianne Miedema (78 goals, 34 assists).
Chelsea beat Leicester 5-2 to stay top of the WSL. The Blues face Arsenal in a top-of-the-table clash at Emirates Stadium after the international break. More than 50,000 tickets have already been sold and Arsenal Women could sell-out Emirates Stadium for the first time.
West Ham remain above bottom side Bristol City on goal difference.
Elsewhere, Manchester United beat Bristol City 2-0, before Manchester City hammered Tottenham 7-0 in the final game of the weekend.
