Erikstrup scored seven factors within the first half and Washington State went into halftime trailing 27-25.
Washington State hosts Portland on Saturday.
WASHINGTON ST. (14-5) — Erikstrup 3-8 3-5 12, Value 2-5 2-4 7, L.Watts 2-5 5-6 9, Calmese 9-17 6-7 27, Thrastarson 1-6 2-2 4, Wynott 0-2 0-0 0, Gerrits 0-0 0-0 0, Okafor 2-2 2-2 6. Totals 19-45 20-26 65.
SAN DIEGO (4-15) — Trouet 7-17 1-3 17, Jamerson 2-5 1-2 5, Webb 2-3 0-2 4, Clouet 0-1 0-0 0, Duckett 6-12 2-3 14, Chammaa 3-14 4-4 13, Bradley 2-7 3-4 8, Dahlke 0-0 0-0 0, Pierre 0-2 0-0 0. Totals 22-61 11-18 61.
Halftime—San Diego 27-25. 3-Level Objectives—Washington St. 7-23 (Erikstrup 3-7, Calmese 3-8, Value 1-3, L.Watts 0-1, Thrastarson 0-2, Wynott 0-2), San Diego 6-21 (Chammaa 3-8, Trouet 2-5, Bradley 1-4, Clouet 0-1, Duckett 0-1, Pierre 0-2). Rebounds—Washington St. 29 (Erikstrup 10), San Diego 34 (Trouet, Jamerson 9). Assists—Washington St. 13 (L.Watts 5), San Diego 8 (Jamerson, Bradley 2). Whole Fouls—Washington St. 19, San Diego 27. Fouled Out—L.Watts, Duckett. A—1,337 (5,100).