His place, though, could come under threat from Phillips next season when the Cardiff number nine completes a six-figure transfer.

Marshall and Phillips reportedly squared up to each other in the tunnel post-match but Marshall was quick to dismiss talk of a major bust up.

"Mike Phillips has a got a bit of my nature about him. He is competitive and that can drive you to success," said Marshall.

"We are going to be team-mates next season but there is no real issue. The argument was about mirror space in the changing room!"

On the field, Wales fly-half James Hook guided the Ospreys to a comfortable success with a 17-point haul just a week after he amassed 22 points in subduing RBS 6 Nations opponents England at the same ground.

Hook kicked four penalties, a drop-goal and conversion, while tries either side of half-time by centre Sonny Parker and full-back Lee Byrne meant Cardiff were always kept at a safe distance.

The Blues proved a huge disappointment and although full-back Ben Blair scored all their points they finished a distant second as the Ospreys booked a cup final place against Leicester at Twickenham on April 15.

Ospreys head coach Lyn Jones said: "We are pleased to go through. We have some good and bad experiences against Leicester in the Heineken Cup last season and we will look forward to it.

"We played 160 minutes of rugby against them last season and I thought we were the better team for the 140 of those minutes, but Leicester won both game, and they are not in the top two of the Guinness Premiership for nothing.

"Leicester are a pretty positive side, so we might have a cracker of a final on our hands at Twickenham."

Cardiff shot themselves in the foot to a large degree, as English referee Wayne Barnes dished out yellow cards in the first half to Blues forwards Scott Morgan, Deiniol Jones and Robert Sidoli, and they were never seriously able to threaten an Ospreys side superior in all departments.

Blues head coach David Young said: "I thought all three yellow cards were quite harsh, but they happened, and it is very difficult to win when you have 14 men on the pitch.

"The Ospreys put us under huge pressure, but to be honest, we didn't deserve to win.

"The Ospreys were by far the best team. We were out-muscled - they were far to physical for us and they won most of the confrontations across the field."