Marijo Tot's side have propped up the Chinese top flight for much of the campaign, but built on their surprise win against Guizhou Renhe to further bolster their survival hopes.
Yiteng were 4-0 winners last time out and second-half goals from Dong Xu and Rodrigo Paulista this weekend helped them to back-to-back victories, while Shandong's top-three aspirations were dealt a blow.
Cuca's charges have taken just six points from their last five games and sit sixth as a result.
Yiteng's day was improved as their nearest rivals slipped up. Liaoning Whowin threw away a 3-1 lead to draw with Shanghai SIPG, and Henan Jianye went down 1-0 to leaders Guangzhou Evergrande.
Liaoning were on course for a first win in four matches when a second goal from Derick Ogbu gave them a two-goal cushion with 16 minutes remaining at Shanghai Stadium.
However, Wu Lei scored twice inside the final 11 minutes to deny the visitors maximum points.
Henan held out until the 75th minute when Marcello Lippi's champions came to town, but Elkeson ultimately secured victory for Guangzhou - who handed Alberto Gilardino his debut.
Lippi's side stretched their lead at the summit to seven points as a result, with both Beijing Guoan and Guangzhou R&F failing to win a day earlier.
Ten-man Guoan staged an impressive fightback to draw 2-2 with Changchun Yatai after Li Yunqiu had been sent off 13 minutes in.
Sven-Goran Eriksson's R&F side gave themselves too much to do against Tianjin Teda, who are up to fourth, as they fell to a 3-2 loss despite a second-half brace from Abderrazak Hamdallah.
Goals from Paulo Henrique and Giovannni Moreno earned Shanghai Shenhua a 2-0 victory over city rivals Shenxin while Dalian Aerbin and Hangzhou shared the spoils in a 1-1 draw.
Elsewhere, Guizhou and Jiangsu Sainty drew 1-1 at the Guiyang Olympic Sports Centre.
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