Principality Premiership newboys Pontypool were denied a dream start to the season after they were squeezed out by reigning champions Neath 36-31 at The Gnoll.
Pontypool returned to the Premiership as Division One East winners and rocked the four times champions with three tries, including a brace from centre Phil Price.
Geraint O'Driscoll also booted 16 points as 'Pooler' recovered from the loss of prop Nicky Blake, who broke his leg in the second half.
But Ospreys youngster Kristian Phillips and Gareth King both scored twice to save the blushes of last season's double-winners in front of their home crowd.
"We expected it to be difficult and Pontypool didn't disappoint us," said Neath coach Rowland Phillips.
"We were playing against a team we didn't really know much about and we didn't play well enough. It simpy wasn't good enough as far as our standards are concerned.
"We have been successful int he past, but as far as I'm concerend all of that is in the past. We have to build moving forward."
Despite the loss of British Police prop Blake, who is likely to miss much of the rest of the season, Pontypool coach Gareth Lintern was bullish about the start his side made back in the big time.
"We had been looking forward to this game ever since last season. It was a superb performance and we are bitterly disappointed we didn't win it," said Lintern.
Aberavon made the perfect start to the new campaign with a 29-27 victory over local rivals Swansea at St Helen's.
Ian Moore, Dai Pritchard, Richard Morris and Luke Hatherway all went over to clinch a bonus-point victory for the Wizards despite a late recovery by the All Whites.
Richard Kelly crossed twice to clinch two consolation points for Swansea's losing margin and scoring four tries.
Scarlets outside-half Rhys Priestland was on target as Llanelli beat Glamorgan Wanderers 24-13 at Stradey Park. Adam Powell, Daniel Evans and Ian Jones all scored while Priestland kicked seven points.
Ebbw Vale have finished in the Premiership's top four for the past two seasons but were held to a surprise 6-6 by Bedwas.
Dai Langdon and Andrew Williams both converted penalties for the Steelmen but Phil Dollman struck twice to share the points at Eugene Cross Park.
Rory Pritchard and Carl Hocking grabbed tries as Bridgend won 20-8 at Llandovery who saw prop Craig Cross sent off a minute after coming on as a replacement early in the second half.
Wales head coach Warren Gatland and captain Sam Warburton say their first prioirty on Sunday in the opening game of the World Cup is to win against Uruguay and not get overly concerned with points difference.
With only days to go until the biggest rugby competition in the world begins, rugby fans visiting Cardiff this autumn will be able to enjoy a special display at National Museum Cardiff as part of the celebrations surrounding the Rugby World Cup.
Geraint John has taken up the new role of WRU elite coach development manager having arrived in Wales last week. WRU TV caught up with him at the WRU rugby department's strategy day at the Millennium Stadium.
The entire Welsh Rugby Union Rugby Department gathered at the Millennium Stadium earlier this week where WRU Head of Rugby Josh Lewsey looked back on a year where structural and strategic changes have seen significant progress made
The Welsh Rugby Union has released a specially produced video to spearhead a new campaign to help promote the values of rugby union. The video, entitled Let us Play underpins the WRU rugby department's philosophy - to engage, transfer and retain players, coaches and referees.