20 unanswered second half points see the Ospreys secure a second win of the season at Firhill.
Tries from Tommy Bowe and Nikki Walker, along with 16 points from the boot of Dan Biggar saw the visitors home, as they turned around a 16-6 half-time deficit despite being reduced to 14 men early in the second half after Sonny Parker saw yellow.
The Ospreys made 11 changes to the side that lost at home to Leinster last weekend, two of them positional, with James Hook switching to the centre and Tom Smith moving to flanker, while Steve Tandy was handed his first start of the season. There was a change in the second row pairing to the partnership originally named, with Andy Lloyd replacing Jonathan Thomas. Ian Evans was named among the replacements, marking the end to a 10 month lay-off following an ACL reconstruction after he injured his knee playing for Wales against New Zealand last November.
As Glasgow enjoyed the better of the opening exchanges, they drew first blood through a Dan Parks penalty with just two minutes on the clock after Paul James had been penalised for bringing down the scrum. When Tandy was penalised for not rolling away in the tackle four minutes later, Parks duly doubled the lead with his second penalty.
Dan Biggar got the Ospreys first points of the night with a drop goal from just outside the 22 after the Ospreys worked a set-piece from the line-out after being awarded a penalty, making it 6-3 with just 8 minutes gone.
After a slow start the Ospreys started to enjoy some good possession, working the ball through the phases on several occasions, only for their handling to let them down. They suffered a blow when Tandy was forced out of the action with a leg injury, Jerry Collins replacing him, but the visitors were level on 15 minutes Biggar slotted over his first penalty of the night.
It was an interesting clash of styles, with Glasgow opting for a more direct game with Parks' kicking game pulling the strings, whilst the Ospreys were looking to move the ball through the hands at every opportunity.
It was the home side who got the first try of the night, David McCall scoring in the corner. The score came after the Ospreys had done a good job of disrupting the Glasgow scrum, Chris Cusiter doing well to get the pass away under pressure from Mike Phillips. Rob Dewey took advantage of some blocking in midfield to surge forward powerfully, only to be hauled down inches short of the line by the Ospreys defence. As the ball was recycled, Parks’ cross-kick picked out Kelly Brown near the touch line, who towered over the covering Shane Williams, allowing him to catch and give to McCall, for the centre to touch down on his debut. Parks then added the conversion, before increasing the lead to 10 points with a drop goal two minutes before the interval. Biggar had a chance to narrow the deficit, but his long range penalty was off target, sending Glasgow in at half-time 16-6 up,
HALF TIME: GLASGOW 16 OSPREYS 6
Dan Biggar got the second half off to a good start, kicking a simple penalty just two minutes after the restart after Moray Low was penalised for not binding correctly in the scrum.
The Ospreys were continuing to knock on the Glasgow door without any real success, and they were reduced to 14 in the 50th minute when Sonny Parker was yellow carded after allowing his frustration to get the better of him in the ruck area. The 14 men almost found a way through shortly afterwards though, Duncan Jones, on for Mitchell, combining with Biggar to release Lee Byrne. His charge took him over halfway before he fed Bowe out wide who raced for the line only to get hauled down a metre short.
The breakthrough did eventually just minutes later, and it was a well worked team effort, before some inspirational running by Bowe rounded it off. The initial spark came from Phillips, who ran intelligently from the base of a retreating scrum, and after the Ospreys recycled the ball well it was worked out wide to the Irish winger who accelerated and twisted his way past the covering defence to score, Biggar adding the two points to level it at 16 each.
Despite being a man light, the visitors were dominant at this stage, and they took the lead for the first time just after the hour through a Biggar penalty.
With Nikki Walker introduced in place of Parker after his 10 minutes in the sin-bin expired, Bowe moved to the centre, but it was the Scottish winger who extended the Ospreys lead just a minute after coming on, charging over strongly from close range, Biggar once again converting to make it 26-16.
The Ospreys were in control, but had to be alert to prevent Glasgow taking advantage of a wayward Byrne clearance, Walker doing well to cover and prevent the home side finding a way through.
The final five minutes saw the two packs reduced to passive scrums after the Ospreys lost Mitchell, who had re-entered play in place of Paul James, with Huw Bennett coming back on after he too had already been replaced by Richard Hibbard, who moved across to prop.
The Ospreys played out the closing minutes in a patient and controlled fashion, the forwards keeping possession to run down the clock, with skipper Ryan Jones to the fore as he led his team towards a third consecutive victory over Glasgow, and crucially, a second win of the season.