Welsh internationals Sian Jones and Gwennan Hopkins, centres Molly Anderson-Thomas and Kelsie Webster all crossed for tries to secure the bonus-point.
Fly half Carys Hughes impressed with the boot and Lightning skipper Bryonie King was in thick of all the good things for Gwalia.
The Welsh side travelled north of the border full of confidence after their performance against the reigning champions and league leaders, Wolfhounds, in the last round of fixtures.
They were third in the league before this clash and were will worth their sixth win of this league campaign.
Gwalia’s pack, with their scrum and driving game, proved too much for the home side.
The visitors opened the scoring when scrum half Jones showed her power when she ran hard at the home side’s defence after an impressive driving lineout.
Fly half Hughes added the conversion before the visitors struck again when fellow Welsh international Hopkins powered her way over after a period of pressure to extend Gwalia’s lead.
Gwalia dominated the first half and fully deserved to be ahead on the scoreboard and went in 12-0 ahead at half-time.
After the break Gwalia scored their third try after their first attack of the half when wing Caitlin Lewis put centre Anderson-Thomas.
Fly half Hughes added the conversion to make it 17-0 to the Welsh side early in the second half before Glasgow replied with a try of their own by
Gwalia’s Jenny Hesketh held up Orla Proctor up over the line to save a try before centre Briar McNamara crossed for the home side’s second try to close the deficit to five points.
Lock Alaw Pyrs was then sin-binned for a high-tackle and Gwalia were down to 14 players midway through the second half.
Gwalia survived being a player down and didn’t concede a point before Glasgow scored a third try by replacement Ailie Tucker. Briar McNamara converted to make it 19-17 with ten minutes to go.
Gwalia replied with a try by centre Kelsie Webster after an impressive piece of phase-play by the visitors to go back in the lead. Hughes added the conversion.
Replacement Lily Terry secured the win with Gwalia’s fifth try to keep the Welsh side in the mix for the Celtic Challenge title.
