The Warriors then pulled themselves level when Mark Bennett kicked a long range penalty from the halfway line. And after both defences had remained on top for most of the first half, Glasgow moved ahead with a penalty from Wight after Blues centre Owen Williams was yellow carded.
Things then got even worse for the Blues as a fourth penalty, this time a second from Bennett, meant Phil Davies' side trailed by six at the break.
In the second half, two quick-fire penalties from Patchell got the Blues back on level terms though his third effort after half time, one which would have given his side the lead, went wide.
Despite the young fly-half's miss, the Blues' performance must have been pleasing for Davies, particularly against a side who impressed in last season's PRO12. Bennett may have put another penalty wide but Patchell then continued his good form with the boot, landing a drop goal from 20 metres.
The three points gave the Blues the lead - one they looked like they may hold on to. But when Seymour crossed for the only try of the game, converted by Jackson, it meant the 14 man Blues were up against it.
Macauley Cook was the man to have been yellow carded but the Blues refused to give up. Wales scrum half Lloyd Williams looked to have crossed for what could have been a vital try but the TMO ruled out the score.
Richie Vernon was sin-binned in the process but Glasgow held on.