Bnei Yehuda opened 2007 by upsetting reigning Premier League champion Maccabi Haifa 2-1 at Bloomfield Stadium on Saturday.
Haifa had hoped to rejoin the title race by gaining three points but returned home empty-handed.
Bnei Yehuda was powered by an impressive Lior Asulin brace, which helped his team break out of a 10-match winless slump, while Haifa's 10-match unbeaten streak was broken.
"It just wasn't our day," Haifa coach Roni Levy explained. "Bnei Yehuda turned in a heroic performance. They wanted the win more than us today and all I can do is congratulate them. We'll have to improve sometime soon if we want to defend our championship."
Betar Jerusalem will close out Matchday 15 against Uri Malmilian's Hakoah Amidar Ramat Gan on Sunday night.
Betar has a chance to open a two-point lead over Ashdod SC, which drew 2-2 with Maccabi Tel Aviv.
Betar coach Yossi Mizrahi will be without forwards Omri Afek and Barak Itzhaki, who are suffering from nagging injuries. Toto Tamuz, who has scored four goals so far this season for Betar, will spearhead the team's attack.
Bnei Yehuda 2, Maccabi Haifa 1
Bnei Yehuda opted to play "man-behind-ball" in the first half, settling for the occasional counterattack. The gamble paid off in the 24th minute when Asulin made the most of a Haifa blunder and drilled the ball in from point-blank range.
Haifa equalized nine minutes later. Lior Rafaelov dribbled into the penalty area and played the ball into the path of Gustavo Boccoli, who jabbed the ball into the goal.
Asulin stunned Haifa again in the first minute of the second half, dispatching a looping kick from the edge of the box. Nir Davidovitch responded late and was unable to fist away the ball.
Ashdod SC 2,Maccabi Tel Aviv 2
Host Ashdod dominated the opening stage and the hard work paid off. "The Dolphins" were awarded a penalty in the 19th minute, which veteran striker Shai Holtzman converted.
Ashdod's Gora Tal was sent off in the 54th minute after picking up his second yellow card and Tel Aviv capitalized 17 minutes later when substitute Giovanni Rosso scored off his first touch.
David Revivo gave Ashdod the lead again in the 78th minute by blasting in a spot kick, which was the result of a Tvrtko Kale blunder in the penalty area.
Miljan Mrdakovic earned Maccabi a point by levelling the score in the 82nd minute.
Maccabi Netanya 1, Hapoel Kfar Saba 0
Reuven Atar was welcomed back by the crowd at Netanya's "The Box" for his season debut. Maccabi took the lead in the last minute of the first half when Marius Bundea scored off a sharp Dedi Ben-Dayan cross.
Ben-Dayan was sent off in the 57th minute, and his careless foul led to a Kfar Saba penalty kick. Brazilian striker Jose Duarte was unable to convert.
It was Netanya's first victory following a four-match winless streak.
Hapoel Tel Aviv 2, Maccabi Herzliya 0
After Hapoel had a tough time breaking through the Herzliya defense in the first half, Tel Aviv coach Yitzhak Schum substituted defender Tal Hen at halftime and that led to the desired result.
Ibazito Ogabuna overpowered his marker to head in a close range header in the 54th minute, after being set up perfectly by veteran Yossi Abuksis.
The Nigerian striker scored his second with a strong drive 14 minutes later.
Maccabi Petah Tikva 1, Hapoel Petah Tikva 0
Maccabi entered the derby looking for its first win in four matches. The mission was not easy as Eyal Lahman's club played its trademark physical and aggressive game, rendering the "Luzons" helpless in attack.
Just when it looked like the game was heading towards an uninspiring draw, though, Maccabi scored the winner off a quick counterattack. Omer Golan breezed past the Hapoel defense and provided a cool finish against Barak Visokar.