A penalty from Tao Wei and a late header from Brazilian forward Mendez gave Beijing victory just days after Shanghai Shenhua and Shanghai United completed the merger that has seen them installed as favourites to win the championship.

But the loss was greeted with howls of derision from the Shanghai fans, who called for the ousting of new club owner Zhu Jun, who took control of the club from the city's government-owned holders before merging it with United.

Shanghai trailed with less than 11 minutes on the clock after Guo Hui latched onto a cross from Xu Yunlong, evading the home side's offside trap and leaving him with only goalkeeper Wang Dalei to beat.

Wang, however, hauled Guo down and, from the resultant penalty, Tao made no mistake.

Sergio Blanco missed the opportunity to level the scores with a short-range volley four minutes later while Yin Xifu's powerful effort in the 30th minute was well saved by Beijing keeper Yang Zhi.

Beijing dominated throughout the second half but it took them until the 80th minute to seal the result when Mendez outpaced the Shenhua defence to score just 10 seconds after being introduced into the game by Korean coach Lee Jang Soo.

"Our players beat Shenhua with their fighting spirit," said Lee. "It was just the start and we will keep improving."

The loss was Shenhua's first against Beijing since 1994 when China started its professional football league.

Shenhua coach Osvaldo Gimenez Toledo said: "We apologise to the fans who came to watch the match. We paid the price for making mistakes in defence."

Shenhua will clash with Sydney FC in the AFC Champions League on Wednesday, while China's other representatives in the tournament - defending champions Shandong Luneng - picked up where they left off last season with a 5-2 thrashing of Liaoning Huludao.

Meanwhile, newly promoted Zhejiang Lvcheng drew 1-1 with Qingdao Zhongneng, Wuhan Guanggu held Tianjin Kangshifu 1-1 and Shenzhen Shangqingyin drew with Shaanxi Baorong 0-0.