De Ciman hit a career-high tying four 3-pointers.
The Rams, who never trailed, led 17-3 fewer than seven minutes, led by as many as 25 in the first half and took a 41-23 advantage into the break.
Jaleel Williams scored six straight to cap a 10-0 run which pulled San Jose State (2-25, 0-15) within nine, 60-51, with 7:22 remaining.
The Spartans have lost 17-straight games, tied with Grambling State for the longest active losing streak in Division I.
Williams scored 20 and Rashad Muhammad added 18 for San Jose State.