Arsenal overturned a first-leg deficit to defeat Bayern Munich 2-1 on aggregate in front of over 21,000 at Emirates Stadium.
Frida Maanum gave the Gunners the lead on the night, with a fantastic strike set up for her by Leah Williamson.
Stina Blackstenius headed in the second before the break from close range, with Wolfsburg or Paris Saint-Germain to be Arsenal’s semi-final opponents.
Barcelona earlier breezed through against Roma, watched by nearly 55,000 at the Nou Camp.
Fridolina Rolfo scored twice, Maria Leon netted from outside the box when set up by Keira Walsh.
Asisat Oshoala and Patricia Guijarro then added one apiece, before Annamaria Serturini pulled one back.
Barcelona will face either Chelsea or Lyon in the last four, with their second leg at Stamford Bridge KO 8pm tonight, live on DAZN/DAZN YouTube.