Ospreys make numerical advantage count at Glasgow
Ospreys ran in four tries to earn a 22-5 bonus-point success at 14-man Glasgow and move closer to the top of the Guinness PRO12 table.
Although Ospreys had been the more progressive side - leading 5-0 at the break thanks to a try from scrum-half Tom Habberfield - the result hinged on the red card shown by referee George Clancy to Warriors lock Brian Alainu'uese in the 46th minute.
Ospreys then adopted a much more open style to use the extra man that produced tries for replacement wing Tom O'Flaherty, number eight Dan Baker and centre Ashley Beck.
Glasgow's consolation try was scored by sub wing Junior Bulumakau with 90 seconds left.
It was Ospreys' first-ever win at Glasgow's Scotstoun Stadium and their first in nine visits to Scotland
Glasgow kicked off in bitter conditions but it was Ospreys who controlled the opening stages, though without reward.
Fly-half Josh Matavesi made a clean break but when he reached the home 22 he was foiled by a textbook tackle from home full-back Peter Murchie.
On 12 minutes Matavesi got a second chance to get the scoreboard m oving but he pushed his penalty attempt to the right of the posts.
Glasgow suddenly came alive when left wing Lee Jones regained his chip ahead but Ospreys full-back Dan Evans hauled him down just short of the tryline.
Just when it looked as though the half would end scoreless Ospreys produced a try.
Glasgow lost possession and right wing Daf Howells whacked the ball from his own 22 into empty Warriors territory. Chasing scrum-half Habberfield was first to it to hack the ball on before touching down for a try that was signed off by the television match official.
From the restart Ospreys again took the initiative with Glasgow's task becoming more difficult when Alainu'uese was shown a red card for dangerously entering a ruck.
With Glasgow's defence then drawn inwards, a kick to a wide-open O'Flaherty brought an unconverted try on 50 minutes.
Sensing blood, Ospreys then unleashed a much more open game with Baker touching down close to the posts in the 58th minute, though Matavesi again missed the conversion.
Ten minutes later Beck sidestepped a tackle for the bonus point try with Matavesi adding the extras for the first time.
Glasgow had the last word through Bulumakau but they were well beaten.