Ulster produced an extraordinary response to their opening weekend defeat by brushing aside the Ospreys 20-16 at Liberty Stadium on Saturday.
The Ravenhill outfit proved to be a constant thorn in the out-of-sorts Ospreys' side and deservedly picked up the four points that lifted their spirits.
However, the closing stages were a highly nervous affair for the Ulstermen as Ryan Jones and his charges threw everything at them.
To the contest itself and wing Simon Danielli ran in two of the tries as the visitors ended a fifteen-match losing run to see off their hosts.
Despite having 17 internationals in their 22, including former All Black Jerry Collins, the Ospreys failed to gel in their opening home Magners League game of the season.
They were fortunate in the end to come away with a bonus point, so poor was their display against a side who lost 23-6 to the Dragons.
The match was only four minutes old when the Ospreys went into the lead with a James Hook penalty from the 22.
But Ulster responded impressively with a try just over a minute later. Outside-half Ian Humphreys made a break through midfield before wing Timoci Nagusa put lock Dan Tuohy over down the right to snatch a 5-3 lead after six minutes.
And that became 12-3 in the tenth minute as Jonny Vaughton gave an interception pass straight to Humphreys who broke away and sent Danielli behind the posts.
After an indifferent start the Ospreys came alive with a fantastic try for Nikki Walker made by breaks from Andrew Bishop, in his own half, and Mike Phillips.
There was a hold-up in play for some five minutes for treatment to Tuohy, who appeared to have been knocked out after attempting to tackle the lively Jerry Collins. Tuohy was helped off to be replaced after 26 minutes by Thomas Anderson.
Hook missed two long-range penalty goal attempts, and a minute before half-time Humphreys gave Ulster a seven-point cushion with a penalty goal from right in front of the posts after good work from hooker Andy Kyriacou and flank Willie Faloon.
Ulster then suffered an injury-time setback when full-back Clinton Schifcofske was sin-binned for a professional foul on Phillips.
From the resulting penalty the Ospreys mauled their way over the line, with replacement prop Duncan Jones emerging with the ball. But Hook missed the conversion which would have levelled the scores at the interval.
Just as in the opening period, Hook kicked a penalty four minutes into the half to see the Ospreys take a 16-15 lead which they kept intact when Humphreys missed a penalty a couple of minutes later.
But the Irishmen were back into a 20-16 lead when Danielli grabbed his second try after some neat inter-passing involving Nagusa and Schifcofske.
After that neither side looked capable of scoring with Humphreys missing a long-range penalty attempt five minutes from time. At the final whistle there were audible boos from the home support.
Tries: Walker, D Jones
Pen: Hook 2
Tries: Tuohy, Danielli 2
Ospreys: 15 Barry Davies, 14 Jonny Vaughton, 13 Sonny Parker, 12 Andrew Bishop, 11 Nikki Walker, 10 James Hook, 9 Mike Phillips, 8 Ryan Jones (capt), 7 Marty Holah, 6 Jerry Collins, 5 Andy Lloyd, 4 Ian Gough, 3 Cai Griffiths, 2 Richard Hibbard, 1 Paul James.
Replacements: 16 Huw Bennett 17 Duncan Jones 18 Jonathan Thomas 19 Tom Smith 20 Jamie Nutbrown 21 Dan Biggar 22 Tommy Bowe.
Ulster: 15 Clinton Schifcofske, 14 Timoci Nagusa, 13 Darren Cave, 12 Ian Whitten, 11 Simon Danielli, 10 Ian Humphreys, 9 Isaac Boss, 8 Robbie Diack, 7 Willie Faloon, 6 Chris Henry (capt), 5 Ed O'Donoghue, 4 Dan Tuohy, 3 Brendon Botha, 2 Andy Kyriacou, 1 Bryan Young.
Replacements: 16 Nigel Brady, 17 Declan Fitzpatrick, 18 Tamaiti Horua, 19 Thomas Anderson, 20 Cillian Willis, 21 Niall O'Connor, 22 Jonny Shiels.
Referee: Alan Lewis