Ospreys flexed their forward muscle to battle back and claim a 22-19 BKT United Rugby Championship victory.
12,125 spectators packed into a sold out Cardiff Arms Park and the Blue and Blacks made the perfect start as Owen Lane pounced inside four minutes. However, the Ospreys ground their way back into the game courtesy of their giant pack.
Hookers Liam Belcher and Sam Parry exchanged tries from driving line outs before second half tries from Owen Williams and Dewi Lake put the Swansea-club in the driving seat.
Cardiff opening the scoring after just four minutes at the Arms Park after Liam Williams put his side in the ascent. He collected an Ospreys clearance, set an up and under high before leaping above the opposition to regain possession.
That put the Blue and Blacks on the front foot and moments later Tomos Williams spotted space down the left and trickled an intelligent grubber to the corner. Jack Walsh should have collected but under pressure from Owen Lane, he failed to secure possession and the wing needed no second invitation.
Evans’ conversion crept over from the touchline and Cardiff held an early seven-point advantage, to the delight of the home crowd.
The Ospreys had the opportunity to hit back when they kicked to the corner on 15 minutes and they set up a driving maul with their gargantuan pack. Cardiff held it at bay but they were unable to hold the Swansea-club out in the opposite corner five minutes later. Sam Parry was the scorer and Owen Williams levelled the scores with the conversion.
With unforecast torrential hammering the Arms Park, and the wind at their backs, the conditions were suiting the Ospreys but it was Cardiff that claimed the next score.
Good work from Taulupe Faletau at the breakdown forced the visitors to seal off and from the penalty, Evans went to the corner. Liam Belcher threw long, to Faletau at the back and the pack showed plenty of patience to set up a second drive and power over with Belcher scoring.
Evans failed to add the extras but Cardiff held on and finished the half with a deserved 12-7 lead, however the Ospreys responded in fortuitous circumstances within minutes of the restart.
With Cardiff under major pressure on their own try-line, they managed to disrupt Tomos Williams at the base and he miss-hit his box-kick. Alun Wyn Jones slapped the ball back and it fell to Owen Williams, who appeared to have been in front.
Williams was off-target with conversion but he made amends 10 minutes later after a succession of penalties, kicked to the corner, saw the visitors turn the screw up front. They were held at bay on three occasions before Dewi Lake eventually drove over. The converted try gave the Ospreys a seven-point lead with 25 minutes remaining.
Ospreys were dealt a blow on 64 minutes when Ethan Roots was shown yellow for a tip tackle on Liam Williams. The indiscretion and fired up the Arms Park once more but the Ospreys pack continued to pile on the pressure.
It appeared as though they had won another scrum penalty as the 70th minute approached but referee Adam Jones reset and the Cardiff pack summoned every ounce of energy to win a penalty against the head.
They did not need it however, as they attacked with the advantage and caught the Ospreys narrow. Evans opted for the cross-kick and found Adams, who raced clear of Alex Cuthbert for his seventh try in six games.
Evans slotted the touchline conversion to level the scores and set up a tense finale.