At the Parade, it was the visiting Warriors who took the lead through a Willie Walker try and conversion, but the hosts punished their indiscipline as James Arlidge kicked two penalties.
The fly half will be looking to build on what was an excellent season for him in 2008/09 and his overall performance will have given him confidence that this year he can impose himself both in the Magners, and Heineken Cup competitions.
It was cat and mouse all evening, and the Warriors regained the lead with a Walker penalty after 65 minutes, but Will Harries' try and Shaun Connor's conversion and penalty won it for Paul Turner's side.Visitors Will Bowley and Pat Sanderson were sin-binned in the opening period.
Over in Cardiff, the Tigers fought back from 5-3 down at half-time so quash Cardiff dreams of revenge following last season's agonising Heineken Cup exit.
The home side scored the only five pointer in the first period. New signing Ceri Sweeney's crossed to give his side the lead after Jeremy Staunton's penalty in the first-half got the scoring under way.
Leicester dominated after the break and Staunton added two more penalties to punish the Blues. Jordan Crane, who kicked the winning Heineken Cup semi-final shoot-out penalty in May, touched down from a close-range scrum. At the Liberty Stadium new signing Barry Davies scored and created a second try to send the Ospreys on their way to a comfortable victory over Leeds Carnegie.
Davies, a summer signing from French outfit Brive, was handed the No15 jersey usually worn by Lee Byrne for this opening friendly of the season.
But the former Llanelli Scarlet showed he is ready give the British Lion a fight for a place when the Magners League kicks off with a blistering early attacking display.
Davies slid through a neatly placed kick for wing Johnny Vaughton to race onto for the first Ospreys try, cancelling out Ceiron Thomas' penalty for Leeds.
Just four minutes later and the full-back stepped on the gas himself, scorching in from 20 metres out for his first Ospreys score.
Dan Biggar, Wales fly-half during the summer tour to North America, converted both for a 14-3 lead only for Leeds to cross just before half time.
New Ospreys boss Scott Johnson made the customary raft of changes at half-time, throwing on Ian Gough, Liam Davies, Gareth Owen, Sonny Parker, Ashley Beck, Craig Mitchell, Ryan Bevington and new signing Jerry Collins.
Ex-All Black Collins almost made an immediate impact when his pass sent Owen close before Jamie Nutbrown darted over to put the Ospreys in the driving seat.
Leeds, promoted to the Guinness Premiership this season, hit back twice only for the Ospreys to respond to each try through Ben Lewis and Parker.