Doha, Qatar: Al Shahania stunned Al Rayyan 3-0 to inflict a big blow to the Lions hopes of a top-four finish.
Rayyan are still fourth with 30 points, but Al Ahli, on 29 have a chance of overtaking them with a victory at Al Duhail on Thursday.
Rayyan had lost 0-4 to league leaders Al Sadd last week and the performance against Shahania suggested they were still suffering from the aftereffects of that mauling.
Shahania took an early lead through Rebin Sulaka who sneaked in front of Rayyan defence to control a freekick from the left just in front of Rayyan goalkeeper Fahad Younis before beating him with a left footed shot from close-range.
Shahania doubled their lead with a beautiful goal in the 34th through Sultan Bhakit Al Kuwari.
A long ball from defence found Jean Paul Kesse Mangoua as Shahania launched a quick counter and the Rayyan forward relayed the ball to Al Kuwari who finished first time with aplomb.
Saad Hussein mede it a drubbing with a stunning solo goal, as he ran half the length of the pitch before beating Younis with an equally classy finish.
Earlier Al Kharaitiyat handed Al Gharafa a 3-0 drubbing.
Gharafa, who lost to Zob Ahan in the Champions League playoff, are in ninth position with 19 points, 12 adrift of fourth-placed Al Rayyan.
The Cheetahs had signed defender Lucas Mendes from Al Duhail during the January transfer but their backline was all at sea against Kharaitiyat who led 1-0 at half-time.
Mohamed Razak put them ahead in the 31st minute, taking full advantage of an error from Gharafa goalkeeper Youssef Hassan to chip the ball into an empty net.
Valentin Lazar made it 2-0 in the 61st with a left-footed shot from close range while Abdulaziz Al Ansari completed the tally ten minutes later.
Kharaityat are now on nine points and have a slim chance of survival, even though they are 12th in the table.