The 2010 runners-up from Kuwait claimed a 2-1 win in the first leg at home and visit Jordan for the return meeting.
Khaled Al Qahtani and Musaed Neda netted for the winners, but they may rue conceding a late goal when Rodrigo Carioca struck.
Sitting second in the Kuwait Premier League, Al Qadsia remain unbeaten in the league with Omar Al Soma starring.
The striker has scored eight league goals in six matches to make a blistering start to the campaign.
Bader Al Mutawa has been the man Al Qadsia have turned to in the AFC Cup and he has scored nine times in the competition.
Coach Mohammed Ibrahem will be hoping an early goal could put his side on track for the final for the second time in four years.
Al Faisaly have struggled in the Jordan Premier League since their first-leg loss at Al Qadsia.
They were held to a 1-1 draw at home to That Ras and 0-0 at Mansheyat to sit seventh with just one win from their opening three games.
Scoring just once in their two most recent matches shapes as being a problem for Ali Kmeikh's Al Faisaly.
Al Faisaly are two-time champions of the tournament but the last of those wins came in 2006 when they completed back-to-back title triumphs.
