Tries from Welsh Grand Slam heroes Shane Williams and James Hook - and 13 points from the boot of the latter - helped the Ospreys to a convincing 32-7 win over Ulster in the Magners League at the Liberty Stadium on Friday.
Kieron Dawson scored for the Irish side in the first half of this contest, which was played out in front of a crowd of more than 9,000.
The bonus-point victory sets the Welsh region up for their Heineken Cup quarter-final clash at Saracens a week on Sunday.
But the early pressure came from Ulster, who camped themselves in the opposition 22 but could not get any change out of the Ospreys' staunch defence.
First the Ospreys stopped a line-out drive and then disrupted two five-metre scrums to build on their shut-out of Saracens in the EDF Energy Cup semi-finals last weekend.
And after 16 minutes it was the Welshmen who took the lead with a Hook penalty as Ulster started killing ball at the ruck.
Two minutes later, from a similar position, Hook watched his second penalty attempt rebound off the right upright.
Ulster's indiscipline saw the referee sin-bin prop Tom Court for a ruck offence and the Ospreys responded by scoring two tries in the space of two minutes.
An Ian Gough line-out claim sent Ben Lewis on a run into the 22 before Hook ghosted his way past three tacklers to go over by the posts. Hook improved the score with the conversion to give the home side a 10-0 lead after 25 minutes.
That was followed by a try for Nikki Walker, who was tackled just short of the line but momentum took him over the whitewash to give the Ospreys a 15-0 advantage.
Very much against the run of play, Ulster scored a try in first-half injury-time when Keiron Dawson was awarded a try on the intervention of the TV judge after a run into the 22 by wing Tommy Bowe.
The half-time score of 15-7 remained intact until the 70th minute when Hook converted his second penalty.
And the result was put to bed in the space of three minutes when Williams crossed twice.
First he was put in down the right by Jonny Vaughton and then he won a kick and chase to claim his second - making it nine tries in his last six outings for the Wales wing.
For the Ospreys:
Tries: Hook, Walker, Shane Williams 2
Cons: Hook 3
Pens: Hook 2
Ospreys: 15 Johnny Vaughton, 14 Nikki Walker, 13 Sonny Parker, 12 Andrew Bishop, 11 Shane Williams, 10 James Hook, 9 Justin Marshall, 8 Filo Tiatia (c), 7 Ben Lewis, 6 Jonathan Thomas, 5 Ian Evans, 4 Ian Gough, 3 Cai Griffiths, 2 Huw Bennett, 1 Duncan Jones.
Replacements: 16 Richard Hibbard, 17 Paul James, 18 Alun-Wyn Jones, 19 Tom Smith, 20 Rhys Webb, 21 Shaun Connor, 22 Jonathan Spratt.
Ulster: 15 Bryn Cunningham, 14 Tommy Bowe, 13 Andrew Trimble, 12 Paddy Wallace, 11 Mark Bartholomeusz, 10 Niall O'Connor, 9 Isaac Boss, 8 Stephen Ferris, 7 Kieron Dawson, 6 Matt McCullough, 5 Ryan Caldwell, 4 Justin Harrison, 3 Tom Court, 2 Rory Best (c), 1 Bryan Young.
Replacements: 16 Neil Brady, 17 Declan Fitzpatrick, 18 Grant Webb, 19 Roger Wilson, 20 Kieran Campbell, 21 Rob Dewey, 22 Marc McCrea.
Referee: Peter Allan (Scotland)
Touch judges: James Jones (Wales), Huw David (Wales)
Television match official: Hugh Watkins (Wales)