The Matildas will hunt a second trophy in the continental tournament and first since 2010 against Japan or South Korea, who play in the second semi-final in Sydney on Wednesday.
Scoring in front of home-town fans for the third time in the event, Kerr struck the winner on 58 minutes, threading the needle from an acute angle to send the Perth Stadium crowd into delirium.
Defending champions China had levelled the match with a Zhang Linyan penalty in the 26th minute following an early strike by Caitlin Foord.
Check out the match stats here
