Replacement Niko Matawalu ran in for a try hat-trick as Glasgow ended Ospreys' nine-game winning run at home with a 29-20 Guinness PRO14 victory at Liberty Stadium.
Matawalu came on early in the first half and took advantage of the Warriors' superior attacking threat as they outscored the home side four tries to two. The bonus point triumph increases the Scottish club's lead at the top of Conference A.
As well as Matawalu, centre Nick Grigg grabbed the bonus point score with Thomason adding nine points with the boot. For Ospreys, captain Olly Cracknell and wing Hanno Dirksen went over with Sam Davies kicking 10 points.
Both sides were missing key players because of international calls and injury. Tom Habberfield replaced scrum-half Harri Morgan, who has a calf strain, and prop Ma'afu Fia came in for Tom Botha. In all Ospreys made three changes from the win over Connacht in Bridgend.
For Glasgow, Rob Harley and George Turner, both released from Scotland duty, started at lock and hooker respectively, but Warriors have 13 players in the national side's matchday squad against Wales.
A frenetic opening 15 minutes produced three tries as Glasgow showed their attacking intent.
The match was only two minutes old when lock Scott Cummings broke through resulting in a penalty for the Warriors which Thomson kicked over.
At the other end Ospreys responded with a seventh-minute try as Cracknell crashed over after Rob McCusker and Dan Evans went close. Davies converted.
However, Glasgow stunned the hosts with two Matawalu tries in the space of three minutes. The replacement wing went over initially after receiving a pass out of the back of the hand from DTH van der Merwe and three minutes later went under the posts after a brilliant break out of defence from Grigg after Ospreys' defensive organisation was called into question. Thomson converted both scores.
Davies kicked a penalty in the 26th minute to reduce the deficit to seven points but then missed a penalty shot at goal with the last kick of the half. Warriors led 17-10 at the interval.
Ospreys scored first in the second half through a Davies penalty in the 47th minute but Warriors had much more of an attacking threat and scored two more tries in quick succession.
Matawalu sealed his hat-trick when he latched on to an accurate Thomson crosskick before Grigg ran in for the deserved bonus point try, converted by Thomson, after good work from van der Merwe and debutant Stafford McDowall.
Although Glasgow looked dominant, Ospreys scored a second try five minutes from time when Dirksen regathered Cory Allen's speculative kick. The wing ran in by the posts for Davies to convert and cut the Glasgow lead to nine points.
The home side rallied at the end but could not grab a losing bonus point.