Wu Xi struck the winning goal just before the half-hour mark at the Nanjing Olympic Sports Center to move Jiangsu, who finished with 10 men, level on points with their opponents after five matches.
Even with the firepower of Vagner Love, Luneng were unable to find a way past Guan Zhen in the hosts' goal.
And they were undone at the other end when Xi controlled the ball on the edge of the penalty area and sent a low shot across Wang Dalei and into the bottom corner.
It was the midfielder's second strike of the season and only the second goal that Luneng have conceded this term.
The visitors had chances to level late on and played stoppage time out with a numerical advantage after Ji Xiang was dismissed, but Sainty were able to hang on and record a third win of the season.
