Beijing Guoan failed to take advantage of Shandong Luneng's slip as they suffered a surprise 3-0 defeat to city rivals Beijing Renhe on Saturday night.
The league leaders looked tired for much of the match, with Renhe making the most of that weariness to claim three points that will boost their own chances of avoiding relegation from the Chinese Super League.
Benjamin Moukandjo's close-range shot took Renhe into an early lead before Guoan's Jiang Tao was shown a red card in the 17th minute.
Renhe's Ajub Masika almost doubled their advantage in the 11th minute, but his shot went wide. They didn't wait too long for their second goal though as Masika scored a fantastic solo goal.
Senegalese striker Makhete Diop then finished the scoring with a coolly converted penalty.
Guizhou Hengfeng pulled off a huge upset by beating Shandong Luneng 3-1 on Saturday night. /VCG Photo
Guizhou Hengfeng pulled off a huge upset by beating Shandong Luneng 3-1 on Saturday night. /VCG Photo
Elsewhere, the title contender Shandong Luneng also endured a miserable night, trailing by two goals at halftime to bottom club Guizhou Hengfeng.
Steve Trawally created chaos in the penalty area and another goal changed the score to 3-0 in the 49th minute. Graziano Pelle pulled one back for Luneng in the 81st minute, but it was too late.
Chinese international Wu Lei's last-gasp goal secured the three points when Shanghai SIPG faced Chongqing SRM. The league's top scorer helped SIPG beat SRM 3-2, while his team climbed to second place in the CSL standings.
In the other three games played on Saturday night, Dalian Yifang defeated Henan Jianye 2-1, Tianjin Teda drew with Jiangsu Suning 1-1 and Guangzhou R&F thrashed Changchun Yatai 5-2.
(With input from agencies)