Steele has moved to 16 under with Smith and Matt Jones, both 11 under, the best Australian hopes on Sunday at the Grange Golf Club.
Steele has a bunch breathing down his neck with Louis Oosthuizen, Joaquin Niemann, Andy Ogletree and Mexico's Carlos Ortiz at 14 under.
Former world No.1 Jon Rahm lurks a further shot back at 13 under with Australians Jones and Smith trying to gain some momentum entering their last nine holes.
Matt Jones is among the best-placed Australians as LIV Golf Adelaide approaches its climax. (Michael Errey/AAP PHOTOS)
Smith started Sunday at 11 under but bogeyed the third hole, a 222-metre par 3, before a birdie on the seventh.
Jones has picked up a stroke with the home-country duo among six players at 11 under.
Fellow Aussie Marc Leishman is nine under, with Lucas Herbert a shot further back.
Some notable big names are off the pace, including Brooks Koepka (nine under), Bryson DeChambeau (eight under), Dustin Johnson (eight under), Sergio Garcia (three under) and Phil Mickelson (three under).
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