Neath-Swansea Ospreys claimed the Celtic League crown with a hard-fought victory over Edinburgh at the Gnoll.
Ospreys: (19) 29:
Tries: Spice, Henson.
Cons: Henson 2.
Pens: Henson 5.
Edinburgh: (7) 12:
Tries: Kelly, Dickinson.
Wales centre Gavin Henson continued his Grand Slam form with five penalties, two conversions and a second-half try.
That added to an earlier effort from scrum-half Jason Spice that gave the Ospreys a lead they were never to lose.
Edinburgh played their part in a fitting title finale, keeping doubt in the final result with tries from Andrew Kelly and Alasdair Dickinson.
Henson kept the scoreboard ticking over in the first half-hour with three penalties, before the Ospreys made their early dominance tell.
Number eight Ryan Jones picked up from the base of a scrum and launched himself through the visitors' creaking defensive line.
Fellow back-row Steve Tandy was on Jones' shoulder in support and the flanker shipped the ball right for Kiwi scrum-half Spice to canter over in the corner for a converted try.
Edinburgh soon hit back through Kelly, the hooker shoving Ospreys centre Sonny Parker aside to dive over.
Chris Patterson added the conversion, making up for an earlier penalty miss, but another Henson three-pointer made sure the Ospreys held a handy 19-7 lead at the break.
Henson was on target again within two minutes of the restart, whacking a monstrous kick from inside his own half between the Scottish posts.
Replacement Edinburgh prop Dickinson set a few home nerves on edge when he stood Spice up, rounded the Ospreys scrum-half and went over in the left corner for an unconverted try.
But Henson made sure any doubts were short-lived with an answering try and conversion as the Ospreys fashioned a three-man overlap, prop Adam Jones floating an intelligent pass to the left wing.
Both sides remained committed to attacking, much to the delight of the 10,280 fans packed inside the Gnoll.
But it was the Ospreys who ensured an already great season for Welsh rugby got even better, by adding the Celtic League title to the Six Nations Grand Slam.
Ospreys: S Terblanche; R Mustoe, S Parker, G Henson, S Williams; M Jones, J Spice; D Jones, B Williams (capt), A Millward, B Cockbain, J Thomas, R Jones, S Tandy, J Bater.
Replacements: R Hibbard, A Jones, L Bateman, R Pugh, R Rees, E Seveali'I, A Durston.
Edinburgh: H Southwell; C Paterson (capt), M Di Rollo, B Laney, S Webster; P Godman, M Blair; A Jacobsen, A Kelly, C Smith, N Hines, A Kellock, A Hogg, S Cross, S Taylor.
Replacements: S Lawrie, A Dickinson, F Pringle, D Callam, R Lawson, B MacDougall, M Pyke.
Referee: Alain Rolland (IRFU).