Arazi pulled off one of the biggest shocks of this year's tournament with a surprisingly easy win over the 10th seeded Australian.
Arazi, who was a quarter-finalist at Melbourne Park four years ago, successfully tamed Philippoussis's fearsome serve, breaking him five times while never losing his own service.
The 30-year-old Arazi plays French Open champion Juan Carlos Ferrero in the quarter-finals after the Spanish third seed beat Andrei Pavel of Romania 6-4 3-6 6-3 6-2.