
Harry Kewell and Brett Holman also found the back of the net as Australia cruised to an opening Group D victory.
Four years ago, the Socceroos laboured to a 1-1 draw with Oman but there were no such woes this time around as they outclassed a plucky but limited India side.
Cahill broke the deadlock after 11 minutes when he sidefooted home Brett Emerton's low cross inside the six-yard box after the Blackburn man had advanced unchallenged into the area.
Kewell doubled the lead in the 25th minute with a vintage strike. The former Leeds and Liverpool forward collected Luke Wilkshire's pass on the right and was afforded space to turn before unleashing a swerving left-foot drive that nestled in the far corner.
Cahill spurned an excellent chance to add a third goal after half an hour when a deflected shot broke to the 31-year-old but from close range, he prodded a weak effort that hit goalkeeper Paul Subrata and spun wide.
The Indian stopper then tipped a fierce dipping 25-yard effort from the same player over the bar after Cahill had exquisitely brought down a long ball with his chest before Holman claimed the third in first-half injury time when he beat Subrata to Emerton's cross to head home from six yards.
The second half turned out to be a more pedestrian affair with Australia largely happy to sit on their healthy lead but Cahill added the fourth goal in the 65th minute when he outjumped everyone in a crowded box to power Wilkshire's free-kick from the right into the bottom corner.