The Devils relied heavily on Ryan Fisher, who had a couple of race wins, including a six-point tactical ride, in his 14-point return.
Their only other heat winner was reserve Todd Kurtz with Glasgow providing the first man home in 12 heats.
Scunthorpe’s Theo Pijper, guesting for skipper Kyle Newman, who was on duty with Poole in the Elite League, managed five (paid six) including a couple of second places.
Plymouth remain seventh in the table, five points behind sixth-placed Ipswich with two home matches in hand over the Witches, who are due at the St Boniface Arena on Friday evening.
Devils co-promoter Ashley Taylor said: “It will be important that we get back to winning ways against Ipswich and make sure that they do not go away with any points from the Arena.
“We need to keep on course in our bid to reach the play-offs and get as high up the league table as possible.”
Glasgow: Richie Worrall 7 (4 rides), James Sarjeant 7+2 (5), Aaron Summers 8 (4), Kauko Nieminen 7+1 (4), Richard Lawson 14 (5). Reserves: Victor Palovaara 8+1 (4), Hynek Stichauer 1 (4).
Plymouth: Theo Pijper 5+1 (4 rides), James Wright 1+1 (3), Jack Holder 7 (5), Morten Risager 2 (4), Ryan Fisher 14+1 (5). Reserves: Sam Simota 6+3 (5), Todd Kurtz 6 (4).