Chang's single came after Weigiang Meng opened the eighth with a single and Brazilian pitchers walked three consecutive batters. The third walk forced in a run just before Chang singled to left for a 3-2 Chinese lead.
A hit batter and two more run-scoring walks completed the rally.
The Pool A win guaranteed China (1-2) a spot in the 2017 WBC while Brazil (0-3) will have to qualify for the next tournament.
Earlier round-robin results allowed Cuba and Japan, both 2-0 in Pool A, to advance to this year's WBC second round. China and Japan play Wednesday for the group title.
Jiangang Lu (1-0) pitched the final 2 2/3 innings for China in picking up the win while Brazil's Murilo Gouvea, who allowed one hit, walked three and struck out three in 3 1/3 innings, took the loss.
Brazil's Daniel Matsumoto, who had been hit by a pitch, scored the game's first run on a J.C. Muniz single in the second inning. Three consecutive singles loaded the bases for Brazil in the seventh before Tiago Magalhaes scored on a fielders' choice, putting Brazil ahead 2-0.