Wagga defeated Yass, making 225 runs in 50 overs, and bowling out Yass 10/175 in the 42nd over on Sunday.
Top order batman Matthew Tom top scored with 67 runs, and Adam Newcombe also made a strong contribution (39).
Wagga had slow start on the field, 2/142, but once Tim Hazell was stumped by wicket keeper Lachlan Kendall, Wagga gained momentum.
Bruce Tom had an economical bowling innings, taking three wickets for 15 runs.
Sean Gaynor spooked Yass, taking out two top order batsman, Daniel Poidevin caught and bowled, and Phil Sparnon bowled for four.
Mitch Cawley was also handy on the bowling front, taking three wickets.
Wagga will face Cootamundra, Yass, Tumut and Gundagai in upcoming rounds.