Dave McCall touches down for a try on his debut.

The home side were thankful for the fervent Glasgow support, but if the vocal home crowd was their 16th man, then the Ospreys’ additional member must have been referee Simon McDowell who failed to spot numerous occasions of foul play infuriating the 3,108 Warriors fans who descended on Firhill.

After the game, Warriors head coach Sean Lineen admitted he was frustrated by the performance of some officials, but did concede that is was not the reason his side lost the game.

“The first half was outstanding,” he said. “We lost the contact battle in the second half and we just couldn’t build any momentum. We needed to improve at the contact to get any kind of platform.

“It was a very frustrating second half after such an impressive first half.

“I’m really proud of the way the players stuck in but we’ve got to win all our home games if we’re to be in with a chance of making the play-offs.”

The Warriors crept into a 6-0 lead with two early penalties from Dan Parks. But they were soon cancelled out by the boot of his opposite number Dan Biggar.

Just as Glasgow really began to turn up the heat, Chris Cusiter unleashed Rob Dewey with the most impressive of passes round the back of Mike Phillips.

Dewey rampaged up the midfield and eventually found Graeme Morrison who tidied up proceedings.

Parks then executed a beautiful cross-field kick to flanker Kelly Brown who gathered and popped possession to Dave McCall who crossed for his debut try.

Parks slotted a drop goal a minute before the break to give the home side a well earned 16-6 half-time lead.

Andy Lloyd tries to drag Tim Barker to the floor.

Half time score: Warriors 16-6 Ospreys

Despite Glasgow building a strong first half platform from which they were looking to win the game, the Ospreys imposed themselves effectively at the contact are to ensure they were soon back in contention.

Biggar grabbed an early penalty before Tommy Bowe ran a simple angle to ease his way through the Glasgow defence and cross for the visitors’ first touch down to level the score. Bowe’s score came with Ospreys a man down after Sonny Parker was sent to the sinbin for a blatant shoulder charge over the top of the breakdown.

Another Bigger penalty followed before they added a second try to give them the advantage after the hour mark.

McDowell failed to spot an obstruction but with the ball in the hands of Scotland internationalist Nikki Walker, the giant winger ran over the top of Dave McCall and Rob Dewey to cross the whitewash.

Glasgow Warriors: Bernardo Stortoni; Rob Dewey, Dave McCall, Graeme Morrison, Thom Evans; Dan Parks, Chris Cusiter; Jon Welsh, Dougie Hall, Moray Low, Tim Barker, Alastair Kellock CAPTAIN, Kelly Brown, John Barclay, Johnnie Beattie
Substitutes: Mark McMillan for Cusiter (half-time), Richie Vernon for Brown (57 mins), Pat MacArthur for Hall and Dan Turner for Barker (both 63 mins), Hefin O’Hare for Dewey (66 mins), Colin Gregor for Stortoni (70 mins), Kevin Tkachuk for Welsh (73 mins)

Ospreys: Lee Byrne; Tommy Bowe, Sonny Parker, James Hook, Shane Williams; Dan Biggar, Mike Phillips; Paul James, Huw Bennett, Craig Mitchell, Alun-Wyn Jones, Jonathan Thomas, Tom Smith, Steve Tandy, Ryan Jones CAPTAIN
Substitutes: Richard Hibbard, Duncan Jones, Ian Evans, Jerry Collins, Jamie Nutbrown, Gareth Owen, Nikki Walker