"Winning is great," said Austin. "I haven't won enough to think that it certainly comes easy so I know how important it is whether it's a two-man team tournament or what have you."
It was Calcavecchia's second Shootout victory, while Austin became the seventh player to win it in his first try.
The winners split a $700,000 first-place check.
Defending champions Rod Pampling and Jerry Kelly (62) shared third with Steve Elkington and Scott McCarron (62), Scott Hoch and Kenny Perry (62), Chris DiMarco and Camilo Villegas (59) and Fred Funk and Jeff Sluman (61) at 24-under 192.