DOLPHIN 16 CORK CONSTITUTION 18, Musgrave Park
Scorers: Dolphin: Try: Nick Williams; Con: Barry Keeshan; Pens: Barry Keeshan 2; Drop: Barry Keeshan
Cork Constitution: Tries: Daragh Lyons, Simon Zebo; Con: Daragh Lyons; Pen: Richie Lane; Drop: Daragh Lyons
Dolphin's unbeaten home run in AIB League and Cup rugby, which stretched back to March 2007, fell as tries in either half from Daragh Lyons and Simon Zebo helped Cork Con maintain their cup run.
Dolphin made a confident start, moving into a 3-0 lead in the 11th minute thanks to a penalty from Barry Keeshan, 40 metres out.
But the home side were clearly missing the guiding presence of number 8 James Coughlan, who is on duty with the Ireland Sevens squad, and they lost hooker Andrew O'Driscoll to the sin-bin midway through the first half.
By that time, Richie Lane had levelled for Cork Con from a penalty and the points were soon flowing for Brian Walsh's side.
A neat pass from John Stringer, brother of Munster and Ireland's Peter Stringer, set up his half-back partner Daragh Lyons for a run at the Dolphin defence.
Lyons duly broke the line and from 30 metres out, he sliced his way through the cover to touch down under the posts.
Lyons added the conversion and with Cork Con now dominating proceedings, he added a drop goal after Keeshan saw yellow.
That left the visitors 13-3 up at the break and they improved the scoreline in the third quarter when junior player Zebo crossed the whitewash for an unconverted try.
But Dolphin rallied in typical fashion and set up a thrilling finale.
After Lane was sin-binned in the 59th minute, Dolphin's big Munster back rower Nick Williams piled his way over the line for a seven-pointer.
Keeshan added a drop goal and a penalty to cut the gap to 18-16.
Agonisingly though, just when Dolphin looked like they might nose ahead Keeshan blotted his copybook.
He fired a drop goal attempt off an upright and from a position just inside the Cork Con half, in injury-time, he watched as a last-gasp penalty effort dropped short of the posts.