Rosso was the first to score, giving Oxy a 1-0 lead in the 16th minute. He also assisted on Dunning's goal in the 78th minute and then Walsh finished off the game with an insurance goal in the 80th on an assist by Santiago Bedoya-Gallego.
Rosso is tied for the conference lead with three assists this season.
Johnny DeRueda evened the score at 1-1 in the 19th minute.
The Tigers outshot La Verne 16-8.
Oxy improves to 4-3 overall and 3-2 in SCIAC play. The Tigers currently sit in fourth place in the conference standings having already played the top two teams Redlands and Cal Lutheran.
The Tigers return to Jack Kemp Stadium on Wednesday, facing Claremont-Mudd-Scripps at 7 p.m.Follow Oxy Athletics on Twitter Sign Up for Newsletters Watch on Youtube Follow us on Instagram