Visually-impaired McGlynn, 41, from Glasgow and her guide Haston from Edinburgh, took 2nd place in the para-sport 1000m tandem time-trial.
It is a second victory for the pair who took silver at Thursday's tandem sprint.
They were narrowly beaten in both races by English women Sophie Thornhill and Helen Scott.
Thornhill and Scott, racing last and with the time to beat staring down at them from the big screen, gained a second inside just two time-spilts.
They continued making gains and had a commanding lead of 1.455secs by the halfway stage, making the second 500m a case of mere preservation.
They ended up 1.584 in front of the Scottish duo but were given an appreciative roar by the Glaswegian crowd.
Despite being a triple Paralympic gold medallist - winning gold in Athens in 2004, taking two more in Beijing in 2008, then silver and bronze in London 2012 - this is McGlynn's first Commonwealth Games.