The Ospreys lost 43-7 to Ulster in Belfast on Friday night. David Humphreys led the scoring for the home side with 23 points in a win which lifted Ulster above the Scarlets in the Magners League overnight.
An early penalty from Ulster was soon wiped out by a superbly taken score from Ospreys full-back Lee Byrne.
The Ospreys, playing their fourth game in just over a week, showed great pace after Justin Marshall's flat pass sent Gavin Henson into space before Byrne got the touchdown in the corner. James Hook's excellent touchline conversion gave the Ospreys a four-point lead, but their scoring ended there.
Humphreys narrowed the gap to a point with a great strike from just over 50 metres.
Ulster took the lead in the 28th minute when a well-worked lineout move saw Rory Best squeeze in at the left corner and Humphreys kicked the conversion to give the home side a 13-7 advantage.
Humphreys added another penalty five minutes later after Ryan Jones was sent to the sin bin for persistent killing of the ball.
He was again on target three minutes later, this time from 55 metres.
Hook then missed the target, and the Ospreys misery continued when they were reduced to 13 men following the injury-time sin-binning of Alun Wyn Jones for what appeared to be a late tackle.
Humphreys arrowed the subsequent penalty wide, meaning Ulster's lead remained 12 points at the interval.
Six minutes after the restart, and with only Ryan Jones back from the bin for the visitors, Ulster crossed the Ospreys line again as Tommy Bowe took an inside line off Paddy Wallace. Humphreys added the two points to make it 26-7 to the home side.
Ulster's push for a bonus point was helped a minute after the hour mark when an Isaac Boss break put Paul Steinmetz clear to make the two points a formality for Humphreys.
The bonus point duly arrived courtesy of substitute Neil McMillan and Humphreys again made it a seven-points.
Final Score Ulster 43 Ospreys 7