After Kim Little had broken the deadlock from the penalty spot, Beth Mead and Danielle Van De Donk gave the hosts a 3-0 half-time lead.
Goals from Noelle Maritz, Jordan Nobbs and Vivianne Miedema made it 6-0 before Jill Roord marked her final Arsenal appearance with a goal.
Maritz then got her second of the match and Katie McCabe made it nine in stoppage time.
Meanwhile, Casey Stoney's Manchester United reign ended with a fifth-round exit at the hands of Women's Championship winners Leicester, as the Foxes enjoyed more FA Cup success in a 3-2 victory at Leigh Sports Village.
Stoney, who is leaving her post after three years in charge at United, saw Jess Sigsworth open the scoring.
Shannon O'Brien pulled Leicester level before the break but Jane Ross put United back in front in the second half.
Quickfire goals from Hannah Cain and Natasha Flint then saw Leicester take the lead and they held on to ensure they will be in the quarter-final line-up when the competition resumes next season - and in with a chance of emulating their club colleagues who won the men's competition on Saturday.
Manchester City swept West Ham aside, winning 5-1 to secure their berth in the last eight.
After Ellen White's opener had been cancelled out by Anouk Denton, City regained the lead through Janine Beckie to head into the break with a 2-1 advantage.
Substitute Rose Lavelle made it 3-1 in the second half before Sam Mewis and Lauren Hemp added gloss to the scoreline in stoppage time.
Kit Graham's extra-time winner saw Tottenham beat Sheffield United 2-1.
The teams were locked at 1-1 after 90 minutes as United's Lucy Watson cancelled out Lucy Quinn's first-half opener.
But Graham headed home in the second half of extra time to send Tottenham through.
Brighton booked their place in the next round with a comfortable 6-0 win over third-tier Huddersfield.
Efforts from Nora Heroum and Rianna Jarrett and an own goal put Brighton 3-0 up after 33 minutes before Heroum missed a chance to add to her tally before the break as her penalty was tipped over the bar.
Fliss Gibbons made it 4-0 in the second half before Danique Kerkdijk added a brace to wrap up a comprehensive win.
Birmingham manager Carla Ward signed off with a 3-2 win against fourth-tier Southampton.
A close-range shot from Mollie Green in the 37th minute gave WSL side Birmingham a first-half advantage.
Emily Murphy doubled the Blues' lead just before the hour mark, heading home from Sarah Mayling's corner before Mayling got her name on the scoresheet in the 66th minute.
Southampton pulled a goal back through Caitlin Morris in the 84th minute before Ella Pusey made it 3-2 two minutes later but Birmingham held on.
Jess King scored Charlton's only goal as they beat Championship rivals Blackburn 1-0.