Chris Oakes added 16 points for SJSU (3-3), and also grabbed 14 rebounds, while recording five blocks in the win.
Gyno Pomare netted 18 points and grabbed eight rebounds for San Diego (4-5), while Matt Dorr chipped in 10 points in the losing effort.
Despite shooting a pedestrian 40.0 percent from the floor in the first half, the Toreros were able to go into the break with a slim, 27-25 advantage.
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The Spartans used a 50.0 percent shooting effort from the field in the second stanza en route to the four-point win.
San Jose State overcame 24 turnovers by shooting 45.5 percent from the field, and 55.6 percent from long range.