UC Santa Barbara took its first lead of the game on McLaughlin's jumper that made it 40-39 at the 15-minute mark of the second half.
The Jaguars (3-10) opened the game on an 11-1 run and never trailed in the first half, going into the break with a 34-26 lead.
McLaughlin was 3 of 5 from 3-point range and the Gauchos were 8 of 15.
Ahsante Shivers led Southern with 22 points.
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