Connacht remain nailed to the bottom of the Celtic League table as Ospreys replacement Shaun Connor rescued the champions' season in controversial circumstances on Friday night.
Connor came on at the start of the second half and slotted four goals, but his side were still trailing 17-15 in the 81st minute when Scottish referee Rob Dickson became the centre of attention.
Connor missed a long-range penalty attempt and Connacht dallied before dropping out from the 22m line. Dickson lost his patience and gave Connor another chance at goal from directly in front. The Ospreys fly-half made no mistake and the better side on the day came second on the night.
It was a poor spectacle at the New Stadium, with neither side getting close to the standard expected at this level. Tries were as rare as a Welsh fan who hadn't heard about the Grand Slam victory as two evenly matched teams tried to bumble their way to a defeat.
Ospreys fly-half Matthew Jones banged over a penalty goal after only 80 seconds, but it was to be his last look at the posts. Opposite number Paul Warwick had the next five shots at goal, converting three of them, as the visitors dominated the opening half.
Scrum-half Conor O'Loughlin was a thorn in the Ospreys' side as his darting runs left the Celtic League champions not knowing where to look - except at the scoreboard where they trailed 9-3 at the break.
Lyn Jones gave his side a dressing-down at the break and immediately swapped Jones for Connor, who narrowed the margin to three points with a penalty goal in the opening exchange of the second half.
The three points woke the crowd up, but they settled back in their seats as Warwick added a fourth goal. Connor made it 12-9 as everyone started giving up on the possibility of a try, before leveling the scores from halfway.
Jones' decision to send Connor on looked like a moment of genius as the home side took the lead with the fly-half's fourth goal when Connacht lock Chris Short was yellow-carded for some reckless rucking on Ospreys backrower Andy Lloyd.
And then came what looked like the killer blow. Winger Darren Yapp - who was a threat all night - ignored the one-man deficit to break clear and give centre Keith Matthews a clear run to the line for the game's first try.
Connacht held the lead as the clock ticked past 80 minutes, but they were pipped at the post.
Ospreys: A Cashmore; D Karauna, A Bishop, L Davies, S Williams; M Jones (S Connor 40), J Spice; D Jones, B Williams (capt) (H Bennett 66), A Jones, B Cockbain (A Newman 55), I Evans, J Thomas, S Tandy (L Beach 47), A Lloyd.
Scorers: Pens - M Jones, S Connor 5.
Connacht: M Mostyn; C McPhillips, J Hearty (T Robinson 59), K Matthews, D Yapp; P Warwick, C O'Loughlin (C Keane 64); R Hogan, J Merrigan (J Fogarty 55), S Knoop; C Short, A Farley (capt); M Swift (C Rigney 34), B O'Connor, J Muldoon.
Scorers: Try - K Matthew; Pens - P Warwick 4.
Halftime: Connacht 9-3.