By beating the Saracens at the Millennium Stadium, the Ospreys have a chance to avenge their defeat to Leicester in last season’s final.
Shane Williams continued his stunning form with two more tries either side of scores from Gavin Henson and Filo Tiatia while James Hook booted 10 points.
The emphatic victory set up a re-match of last year’s final against Leicester Tigers at Twickenham next month, and inflicted a significant psychological blow against their Heineken Cup quarter-final opponents and made sure the feel-good factor in Welsh rugby continued.
Ospreys Coach Lyn Jones named nine of the Wales team who started against France in the Grand Slam finale seven days earlier and the confidence within the squad was obvious from the start.
Williams and Jonathan Thomas both had tries disallowed in the opening five minutes as the Ospreys started in fifth gear. But they only had a single Hook penalty to show for it until Williams pounced on the stroke of half-time.
Saracens fly half Glen Jackson fumbled under Henson’s challenge, Williams hacked ahead twice before speeding past three defenders to win the foot race.
Jackson got the first points of the second half to reduce the gap to 8-3 but it was the closest they came to making a mark on the scoreboard. Henson bumped off Andy Farrell for his score on 50 minutes before the strength of the Ospreys’ bench proved decisive, Tiatia charging over just 90 seconds after stepping into the fray.
Williams put the wraps on a stunning week, racing onto a deft kick from second row Ian Evans that summed up the difference between the teams.
Scorers
Ospreys
Tries: S Williams (2), G Henson, F Tiatia
Cons: J Hook (2)
Pens: J Hook (2)
Saracens
Pen: G Jackson
Referee: Wayne Barnes (RFU)
Attendance: 41,018
