An ally of President Xi Jinping is the new mayor of Beijing, putting him in strong contention for a spot in next year's new Chinese Communist Party (CCP) Politburo.
Mr Cai Qi, who will turn 61 next month, has been named acting mayor and deputy party boss of Beijing, succeeding Mr Wang Anshun, 59, who is reportedly heading to a government think-tank.
At a swearing-in ceremony yesterday, Mr Cai pledged to align his thought, politics and actions alongside the "central leadership with Comrade Xi Jinping as its core", echoing a phrase used at a CCP conclave last Thursday that named Mr Xi as the party's new "core" leader.
Observers said Mr Xi's "core" status - which means his authority cannot be questioned and puts him in the same group as Mao Zedong, Deng Xiaoping and former president Jiang Zemin - makes Mr Cai a shoo-in to take over Beijing party boss Guo Jinlong's post and his place in the Politburo.
Whoever is party boss of one of China's four municipalities - Beijing, Shanghai, Tianjin and Chongqing - inevitably also lands a seat in the 25-member Politburo.
"As the 'core' leader, Xi is now in a strong position to secure top jobs for his allies. There is probably no room for rival factions to bargain with Xi," Beijing-based analyst Hu Xingdou told The Straits Times.
Professor Hu said Mr Cai's familiarity with Mr Xi also puts him in pole position to succeed Mr Guo, 69, who is set to retire in a leadership reshuffle next year. He has already exceeded the unofficial retirement age of 68 years.
Mr Cai worked in Fujian province from 1978 to 1999 and then in Zhejiang province until 2014, when he became deputy director of the National Security Commission, set up in late 2013 to coordinate and oversee national security issues. It is chaired by Mr Xi, who spent 22 years in Fujian and Zhejiang from 1985.
Mr Cai's appointment is seen as part of efforts by Mr Xi and CCP disciplinary chief Wang Qishan to put allies in key positions ahead of the 19th Party Congress next year.
Last Saturday, Mr Jiang Chaoliang, Mr Wang's former subordinate, was promoted from governor of north-eastern Jilin province to party boss of central Hubei.
Prof Hu said Mr Wang Anshun, who helmed Beijing's political and legal affairs commission from 2007 till he became mayor in 2012, might have been penalised for his links to disgraced security czar Zhou Yongkang.
Another factor could be the Beijing city government's poor handling of the smog problem, which drew criticism from Chinese state media in late 2014, said Prof Hu.
Correction note: An earlier version of this story said Mr Jiang Chaoliang was formerly the governor of Liaoning province. This is incorrect. We are sorry for the error.