The Tartans (7-13, 3-4) took care of the Highlanders 33-31, 25-22, 23-25, 25-22.
Leading Glendora was Cassandra Freitaz with 12 kills and six blocks as Casie Lowden and Becca Lowden each added 10 kills to assist Glendora in the win.
With the loss Upland dropped to 6-16 overall and 2-5 in league play.