It was sweet revenge for the Ospreys who lost to the Tigers in last year's final and the best possible way to bounce back from the disappointment of their European exit.
Those defeats were well and truly forgotten as Lyn Jones's men dominated the English giants in the final. Andy Goode kicked Leicester into a 6-0 lead early in the first half but the Ospreys hit back to get their hands on the silverware.
The Ospreys were desperate to go one better from 12 months ago when they were edged out 41-35 in a Twickenham thriller. But that had not stopped coach Lyn Jones shaking up his team that lost their Heineken Cup quarter-final at Saracens last week. Wales stars Ian Gough, Jonathan Thomas, Huw Bennett and Duncan Jones all dropped to the bench while Gavin Henson was ruled out with an ankle injury.
Conditions looked to favour Leicester as the heavens opened before kick-off but that didn't stop fly half Goode having a shot at goal from inside his own half, though his third-minute strike fell well short.
The Tigers' marksman was on target when he opened the scoring two minutes later and the Ospreys had their backs pressed firmly against the wall. The Ospreys' defence had to be at its best to withstand the onslaught as Ollie Smith, Ben Kay and Jordan Crane all went within inches of the try line.
Hook put in a telling tackle but his over-weighted drop-out gave Leicester an attacking scrum from which Goode doubled Leicester's lead with a drop goal. But unlike last year when the Ospreys found themselves 28-9 down in the first half, the Welsh region stopped Leicester in their tracks to take the lead before the break.
Hook looked lively and skipper Ryan Jones galvanised the forwards to mount the Ospreys' first sustained attack before Henson's replacement, Andrew Bishop, stormed through four Leicester tacklers to drive over the game's first try on 22 minutes.
Hook, who missed his first attempt at goal, converted for a 7-6 lead that they failed to build on before half time. Hook was off-target again with a second penalty while breaks by Lee Byrne and Justin Marshall went unfinished.
But Alun Wyn Jones was clinical when he finished Byrne's break to put the Ospreys ahead 14-6. Byrne broke a series of tackle sin midfield, Johnny Vaughton switched direction and Hook put Jones over on 47 minutes.
Leicester threw one final huge effort into scrambling a way back into the game on the hour when they were camped on the Ospreys try line. But a huge defensive effort during four consecutive scrums saw the Welsh team hold out.
The game broke wide open in the last ten minutes and Shane Williams thought he had put replacement Gareth Owen over but his pass was ruled forward. However, Hook kept his cool and stroked over two more penalties to guide the Ospreys to glory.