Nine minutes earlier Kerevi scored out wide after being put through a gap in Argentina's defensive line by Quade Cooper.
The Wallabies flyhalf dummied and delayed his pass before finding Kerevi with an inch-perfect ball.
It was part of an impressive passing display from Cooper during his hour on the field before he was replaced James O'Connor.
However it was Kellaway who secured man-of-the-match honours with his three-try performance.
Kellaway cross for five-pointers in the 34th, 54th and 58th minutes in the Wallabies' five tries-to-two bonus point win.
Both sides missed early penalty goals before Cooper put 3-0 ahead in the 10th minute following a scrum infringement from the Pumas.
The Wallabies gained control of the contest after Pumas lock Tomas Lavanini was yellow-carded in the 27th minute for repeated infringements.
During Lavanini's 10 minutes off the field the Wallabies scored two tries.
The first came less the 60 seconds after Lavanini's exit when Wallabies lock Izack Rodda secured possession from a lineout close to Argentina's line.
A rolling maul followed, with hooker Folau Fainga'a gaining possession to score the first try of the contest.
Fainga'a's impressive performance continued seven minutes when he fed rampaging No.8 Rob Valetini, who in turned delivered perfectly time pass for Kellaway, who scored next to the posts.
The Wallabies went into halftime leading 15-3, and they put game out the Pumas' reach with Kellaway's two second half tries.
Argentina made the scoreline a little more respectable with a pair of tries to replacement Thomas Gallo in the 63rd and 72nd minutes but it was too little too late as the finished their Rugby Championship campaign without a win and with six successive losses.
For Australia, 38-year-old prop Greg Holmes came off the bench to make his first Wallabies appearance since 2016.
Towering back-rower Sean McMahon also came on for his first appearance for the national side since 2017.
