The 17-year-old crushed Taiwan's Tsung-Hua Yang in straight sets, winning 6-2 6-1 6-1 on Margaret Court Arena.
The match was a replay of the 2008 Australian boys final, which Tomic also won.
Tomic's power play and stinging backhand was too much for Yang to handle as he was continually forced into errors.
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Victorian Peter Luczak will face Chu-Hun Yi in the second singles match.
Australia is heavily favoured to win the Asia Oceania Zone Group I tie which continues on Saturday with the doubles and on Sunday with the reverse singles.
The 17-year-old Tomic was preferred ahead of the higher-ranked Carsten Ball to win a singles spot, alongside Peter Luczak for the zonal tie.
At 17 years and 135 days, Tomic is Australia's youngest player since Vivian McGrath played at the age of 17 years 84 days against Norway in 1933, Tennis Australia said.
