Cardiff Blues claimed their first Guinness PRO14 win at the Liberty Stadium since 2005 as they battled back to claim a dramatic victory in the first festive derby of the campaign.
Wales’ Capital Region trailed 10-6 at the interval after the Ospreys benefitted from marginal decisions and were awarded a penalty try.
They stretched their lead in the second-half before battling back and taking the lead thanks to a Jarrod Evans try.
The tight game came down to a kicking battle, as Jason Tovey slotted the match-winning points with less than 10 minutes remaining.
The Ospreys took an early lead at the Liberty Stadium thanks to the boot of Marty McKenzine after the Blues were penalised at the scrum.
They could have been further in front after a cruel bounce defied Matthew Morgan when Scott Williams grubbered to the corner. However, Cai Evans knocked on over the whitewash in slippery conditions to let Mulvihill’s men off the hook.
Opportunities were few and far between for the visitors in the opening quarter and small errors hampered their progress. But they slowly worked their way into the encounter and following an encouraging spell Evans levelled the scores.
Cardiff Blues continued to build into the encounter and a delicious set play off a lineout almost unlocked the home defence. Lane took the ball at full pace as first receiver and moved the ball to Ben Thomas on the switch.
The centre was not quite able to find an offload but the Ospreys infringed at the breakdown and Evans nudged his side into the lead.
McKenzie had the opportunity to tie the scores on the half hour mark but he struck the uprights from in front, allowing Josh Adams a long clearance.
The Blues were dealt a blow when Filo Paulo was harshly sin-binned after taking Aled Davies out beyond the ruck. The Ospreys worked their way downfield and matters were made worse as Tomos Williams followed the second-row to the naughty step.
It initially appeared as though Williams had made a fine try-saving tackle to drive Dan Lydiate into touch however the TMO intervened. Replays showed Williams tackled high and he was shown yellow with referee Dan Jones also awarding a penalty try.
Evans had the opportunity to cut the deficit to a single point but his long-distance sailed wide and the score remained 10-6 at the interval.
After a minute of the second-half, Cardiff Blues were restored to 14-men, with Paulo marking his return with a thunderous hit on Davies, but mere seconds went by before they were back to 13 with Josh Adams the latest to see yellow.
The Ospreys laid siege to the Cardiff Blues try-line but try as they might they were unable to break the white wall and knocked on.
However, moments later further indiscipline allowed McKenzie to keep the scoreboard ticking with the Ospreys now enjoying a 13-6 lead.
Cardiff Blues soon introduced Jason Tovey, Olly Robinson and Hallam Amos to breathe life into their assault.
With Evans combining with Tovey, the Blues began to threaten, and they were rewarded with a penalty that the latter slotted to make it 13-9.
Wales’ Capital Region continued to find their groove with Hallam Amos tearing down the right to lay the foundations for a sustained period of pressure.
And on the hour mark they took the lead with scrum-half Williams dinking the ball over the Ospreys rush defence to set-up Evans for a carbon copy of the try he scored two weeks’ ago at the Arms Park.
Tovey added the extras to make it 16-13 before the Ospreys tied up affairs once again three minutes later.
The Blues pressed in the closing stages with a flying Olly Robinson cutting a razor sharp line to hit a Williams flat-pass but he could not hold onto possession as he crashed over.
With Keiron Assiratti and Rhys Gill on in the front-row it was now the Blues that had the edge at the scrum and from the ensuing set-piece they drove through the heart of the Ospreys.
Josh Adams attempted a quick-tap but he was called back and Tovey slotted the points to regain their slender advantage.
Ospreys had their opportunities late on, but a strong Evans tackle forced the returning Tipuric to knock on.