He beat experienced Australian international Kelvin Kerkow 4-9, 8-5, 2-1 after a closely fought game.
Walker lost the first set to Kerkow, who was the standout player when the Asia and Pacific Bowls championships were held in Dunedin in 1995.
This was an outstanding performance by Walker because Kerkow was an Australian representative for 14 years from 1995 to 2008.
Kerkow won the men's singles title at the Asia and Pacific championships in Dunedin. His other highlights were claiming the Commonwealth Games singles title in Melbourne in 2006, and winning bronze medals in the singles and triples at World Bowls in 1996.
In the first two days of the PBA event, the five New Zealand bowlers played five singles games against the five Australians. Walker was the highest-ranked New Zealand bowler after the five games and Kerkow the leading Australian.
Australia claimed back the transtasman trophy for the teams event when it won the first two singles events on the final day.
Ben Twist (Australia) beat Raika Gregory (Waikato) 10-5, 6-6 in the first match and Brett Wilkie (Australia) beat Chris Lourie (Waikato) 10-5, 9-7.
This was the third year of the annual transtasman challenge.
Australia won in 2010 and New Zealand took the teams trophy home last year.
