The Dirtbags took the second game of a three-game series 7-2 on Saturday afternoon.
The Mustangs were ranked No. 1 by Collegiate Baseball Newspaper in the latest weekly rankings released on Monday.
A complete game shutout from sophomore starting pitcher Casey Bloomquist led Cal Poly to a 3-0 victory over Cal State Fullerton.
The Cal Poly baseball team came out on top Thursday with an 8-0 victory over No. 19 Cal State Fullerton.
The Titans are four-time national champions and have captured the Big West title for three consecutive years.