The Chelsea star fired the winning goal from a tight angle in the 58th minute in front of 35,170 spectators in Perth with her fourth goal of the tournament.
"Her presence, her aura, in the squad is huge. She believes in the group and loves playing for the national team," Australia coach Joe Montemurro said of the 32-year-old Kerr.
Now Australia will face Japan or South Korea in the final on Saturday in Sydney.
The Asian Championships also serve as a qualifier for the 2027 World Cup in Brazil, and the four semi-final teams have secured their spots. Two more places will be allocated in playoff matches between the losers of the quarter-finals.
