Dragons fell to defeat in Swansea despite an impressive first half display as a fully loaded Ospreys side wrapped up maximum points in the United Rugby Championship.
Dragons – without Wales internationals Elliot Dee, Leon Brown, Will Rowlands, Aaron Wainwright and Ross Moriarty due to injury – showed plenty of fight and spirit in the loss.
Jared Rosser, Adam Warren and Mesake Doge grabbed tries as the teams served up a breathless opening half of derby rugby.
The home side, who needed a bonus point in battle for the Welsh Shield, pulled clear in the second half to take the spoils from an entertaining encounter.
Dragons, though, did get a deserved try bonus as Lewis Jones scored late on after a superb break from Rio Dyer.
Boss Dean Ryan made four changes to the starting line-up with one eye on next season and the future.
Young playmaker Will Reed, a product of the Dragons Academy, was handed a full debut while there were returns for fit-again Ollie Griffiths, Gonzalo Bertranou and Josh Lewis.
There was also a late change with Chris Coleman (foot) forced out and replaced by Doge.
Gareth Anscombe kicked Ospreys into a second minute lead while opposite number Reed looked assured in the opening exchanges with one delightful kick to turn the hosts.
And it was Reed who was the architect of the opening try of the game as he sent Warren into a gap and the centre showed great awareness to offload in the tackle and send Rosser over.
Reed then produced a sublime grubber for Rosser, after Ospreys coughed up ball, and this time the wing returned the favour as he fed Warren. Reed added the touchline conversion.
Jordan Williams hit a superb 50:22 to give Dragons more front foot ball, but Ospreys this time disrupted play under pressure.
The home side put the squeeze on at scrum time to win possession back and then kicked to the corner before relentless forward power paid off as prop Nicky Smith dotted down.
A penalty for not releasing allowed Reed to add three more to the total before an Ospreys mistake led to a third visiting try.
Ospreys looked to run from deep but lost control and the ball in their own 22 allowing Taylor Davies and Harri Keddie to rattle up close before Doge dived over from close range for a dream 24-7 lead.
Ospreys went to their power game to find a way back, with Number Eight Morgan Morris crashing over after a driving maul did damage.
A slicing break from Michael Collins set up a third try as the full back brushed off a tackle and released Morgan Williams on his right shoulder.
And the turnaround was complete two minutes before the break when - after a yellow card to Taine Basham - Ospreys made the man advantage count as Morris grabbed his second for a 29-24 lead.
Dragons continued to meet fire with fire at the start of the second half and went close themselves before the hosts struck a decisive blow before the hour when Morris grabbed his hat-trick.
Collins got lucky for Ospreys when he touched a long kick from Reed but just stopped it running dead before an overlap left for Dragons was missed by a loose final pass into touch.
Ryan started to unload his bench on the hour with Huw Taylor, Jonah Holmes and Ben Fry all introduced before Sam Davies replaced Reed.
Anscombe kicked deep into the 22 with 15 minutes left and the home side wrapped up the win with scrum half Morgan Williams spotted a gap to dive over under the posts.
Jordan Williams darted into space and between defenders, but his kick ahead was deflected into the hands on Anscombe.
Sam Parry grabbed a seventh try for the home side, despite calls for a forward pass in the build-up, with nine minutes to go.
Dragons grabbed a late and deserved try bonus after Lewis Jones darted over after a break from Rio Dyer.
02m Anscombe p 3-0
06m Rosser t Reed c 3-7
09m Warren t Reed c 3-14
18m Smith t 8-14
21m Reed p 8-17
23m Doge t Reed c 8-24
28m Morris t Anscombe c 15-24
32m Morgan Williams t Anscombe c 22-24
39m Morris t Anscombe c 29-24
54m Morris t Anscombe c 36-24
67m Morgan Williams t Anscombe c 43-24
71m Parry t Anscombe c 50-24
79m Jones t Davies c 50-31
Ospreys: Michael Collins, Alex Cuthbert, George North, Owen Watkin, Keelan Giles, Gareth Anscombe, Rhys Webb, Nicky Smith, Dewi Lake, Tomas Francis, Adam Beard, Alun Wyn Jones, Will Griffiths, Jac Morgan, Morgan Morris
Replacements: Sam Parry, Gareth Thomas, Tom Botha, Bradley Davies, Dan Lydiate, Reuben Morgan Williams, Stephen Myler, Luke Morgan
Dragons: Jordan Williams, Rio Dyer, Adam Warren, Josh Lewis, Jared Rosser (Holmes 61), Will Reed (S. Davies 64), Gonzalo Bertranou (Jones 54), Aki Seiuli (Reynolds 71), Taylor Davies (Benjamin 53-63, 72), Mesake Doge, Joe Davies (Taylor 61), Ben Carter, Harri Keddie, Taine Basham (Fry 61), Ollie Griffiths
Replacements: James Benjamin, Josh Reynolds, Luke Yendle, Huw Taylor, Ben Fry, Lewis Jones, Sam Davies, Jonah Holmes
Referee: Adam Jones (WRU)