The Mustangs fall to 17-14 overall with the loss and will wait for the announcement of the WNIT field on Monday to see who they will face next. Long Beach State improves to 14-17 and advances to the championship game on Saturday.
Kristina Santiago led the Mustangs with her 16th double-double of the season when she scored 21 points and grabbed 12 rebounds. Santiago was seven of 17 from the floor and seven of 11 from the line. Fellow senior, Christine Martin, added nine points off the bench when she hit two of five from long range.
Junior Kayla Griffin scored six points and helped out with seven rebounds.
Long Beach Sate was led by Hallie Meneses with 16 points when she hit three of six from long range. Devin Hudson recorded a double-double with 10 points and 10 rebounds.
Both teams struggled offensively in the first half with Cal Poly leading at the break 19-13. Santiago, who led the conference in scoring this season with 23.4 points per game, was held to seven points in the first half on two of six shooting from the field. She was the only member of the Mustangs with more than one field goal in the period as the rest of the squad combined to go three for 18 from the floor.
Meanwhile, Long Beach State's Hudson and Meneses combined to shoot 5 of 10 from the floor for 12 points, but the rest of the team misfired on all 17 of its field goal attempts. Overall in the period, Cal Poly made 20.8 percent of its field goals, and Long Beach made 18.5 percent.
Both teams shook off their offensive jitters in the second period, with Long Beach State connecting on five of its first eight shots after the break and Cal Poly making six of 11 shots in the first six-plus minutes of the half.
The Mustangs' lead vacillated between five and 10 points during that stretch, until the Beach put together a 9-0 run that brought them to within one, 34-33, with 11:07 left on the clock.
Santiago put an end to the streak, with a jumper in the lane, but a few possession later, the 49ers pieced together a 12-3 run capped off by a pair of Lauren Spargo three-pointers to go up six, 45-39, with 5:38 to go.
Once again, Santiago put an end to the run, this time with a free throw, and Christine Martin's back-to-back threes put the Mustangs back on top, 46-45.
The 49ers leading scorer on the year, Tipsea Moorer, who was held to one point in the first half, gave Long Beach State the lead once again on a lay up with 1:24 to go.
Santiago drew a foul on Cal Poly's next possession, but missed both free throws. Meneses made her pay with 29 seconds remaining and converted a jumper that put LBSU up three, 49-46.
Martin missed a three-pointer with 20 seconds to go, but Santiago grabbed the rebound and Cal Poly called a time out. Ashlee Burns was fouled with 14 seconds on the clock, and she missed both free throws as well. Santiago grabbed the board on the second misfire, and her subsequent lay up cut the lead to one, 49-48.
Cal Poly fouled on the inbounds pass sending Meneses to the charity stripe, and she missed the front end of the one-and-one, but Chantel Dooley grabbed the offensive board. She was subsequently fouled, and drained both free throws putting the 49ers up three, 51-48.
Burns misfired on a three-pointer as the clock wound down, and Long Beach State celebrated its second upset of the tournament.
The 49ers offense in the second half proved to be the difference as they made 50.0 percent (13 of 26) of their shots including six from long distance. They outscored the Mustangs 38-29 after the break, holding Cal Poly to 33.3 percent (11 of 33) shooting form the floor
Overall Cal Poly shot 28 percent from the floor and made just three of 18 from long range. LBSU shot 34 percent from the floor and made seven of 22 from beyond the arch.
Cal Poly held a three rebound advantage (43-40) and turned the over two less times (19-17).