Austin and Calcavecchia, co first-round leaders, finished 36 holes at 20- under-par 124, which is good for a two-shot cushion over tournament host Greg Norman and long-hitting Bubba Watson. That pair shot an 11-under 61 on Saturday.
Defending champions Jerry Kelly and Rod Pampling (64), Scott Hoch and Kenny Perry (62) and Steve Elkington and Scott McCarron (62) are knotted in third place at minus-14.
Fred Funk and Jeff Sluman shared the opening-round lead with Austin and Calcavecchia, but only managed a five-under 67. The only team comprised of two players who are old enough for the Champions Tour share sixth with Anthony Kim and Mark O'Meara, who posted a nine-under 63 on Saturday. The duos are in at 13-under 131.
Chris DiMarco and Camilo Villegas, Brad Faxon and Justin Leonard and Charles Howell III are tied for eighth at minus-11. All three teams managed rounds of seven-under 64 in round two.
Fred Couples and John Daly share 11th with Stewart Cink and Masters champion Zach Johnson. Couples and Daly carded an eight-under 64 to Cink and Johnson's 65 and the squads are tied at 10-under 134.
Sunday's final round will be a scramble and scores are sure to be low.