Smith won the title in Christchurch four years ago and then won the World Bowls title the following year. But she has started badly by losing two of her four games in section play in Adelaide this week.
She went down to Canada's Kelly McKerihen 21-12 and was then pushed out by Norfolk Islander Carmen Anderson 21-16.
Anderson, a former World Bowls champion, won the Asia-Pacific title when it was held in Dunedin in 1995.
Despite the two losses, Smith recorded an important win over world No 5 Siti Zalina Binti Ahmad, from Malaysia, 21-7, in round three.
The women's four of Leanne Curry, Genevieve Baildon, Jan Khan and Jo Edwards beat Hong Kong 29-10 and Fiji 22-10.
The men's pair of Dan Delany and Richard Girvan beat Canada 17-13 but lost to China 15-14 in a cliffhanger.
The men's triples combination of Tony Grantham, Shaun Scott and Ali Forsyth beat Malaysia 13-10 and Norfolk Island 22-8.
