Leaders, Chelsea were handed the blues at the Wa Park after their eight-match unbeaten run in the Glo Premier League was stopped by All Stars.
All Stars, who prior to kick off had endured a poor run of form tuned the tables in their favour, as they stunned the Berekum side with a 2-0 victory.
Two second half goals from Godfred Gyasi and Sam Ocran were enough to lift the mood in Wa and their survival hopes, having gone close to slipping into the relegation zone.
Despite the loss, Chelsea still hold a 10-point lead at the top as title contenders New Edubiase and Aduana Stars both lost away from home.
Aduana's hopes of cutting the gap were suffered in Accra where they were beaten 1-0 by Mighty Jets courtesy a first half strike by Winfred Dormon.
Edubiase succumbed 2-1 to Liberty Professionals at the Carl Reindorf Park. Kelvin Keku and Moro Zakari scored both goals for the home side with Emmanuel Baffoe pulling one back for Edubiase.
Prior to the start of the season, Hearts of Oak were hopeful of crowing their centenary by lifting the title. But events after their showdown at the Len Clay Stadium where they clashed with AshantiGold tells of a different story.
After going down 1-0 through a goal by Daniel Asamoah in a late kick off fixture, Hearts now find themselves in the relegation zone.
The Phobians are third from bottom and would rue how bad their season has panned out but would welcome the one month break to get back on track.
In the other evening game, Asante Kotoko run out 3-1 winners over bottom side B.A. Stars at the Baba Yara Stadium.
Samad Oppong opened the scoring for Kotoko with Michael Akuffo scoring from a spot kick before Awal Mohammed wrapped it up.
Kessben FC played themselves back in contention for honours with a 2-1 victory against Ebusua Dwarfs at the Robert Mensah Stadium.
Kabiru Imoro opened the scoring in the first half as Dwarfs failed to score from the spot after a penalty had been awarded them.
Kwabena Adusei doubled the lead for Kessben from a spot kick in the second half before Francis Gyepi got the consolation also from a penalty.
Kessben now moves to second place, 10 points adrift the top.
Heart of Lions needed a second half goal to beat King Faisal 1-0 at Kpando.
Real Tamale United's hopes of improving their relegation battle was dealt a big blow at the Golden City Park where Berekum Arsenals managed a 1-0 win. Ishmael Fridos scored in the second half to give the Gunners all three points.
Match-day-19 Results
Heart of Lions 1 - 0 King Faisal
Mighty Jets 1 - 0 Aduana Stars
Liberty 2 - 1 Edubiase FC
All Stars 2 - 0 Chelsea
Arsenals 1 - 0 Real Tamale United
Dwarfs 1 - 2 Kessben FC
AshantiGold 1-0 Hearts of Oak
Asante Kotoko 3-1 B.A. Stars