Not often you would say this about the Ospreys under Steve Tandy but they have been a rabble today.

Replacements as Scott Baldwin is replaced by Scott Otten while the Blues bring on tight-head Anton Peikrishvili for Filise.

Dafydd Pritchard
BBC Sport Wales at the Principality Stadium

Blimey. Who saw this coming? This is a rout.

The Blues have been as impressive as the Ospreys have been poor - and that fifth try signified as much.

After some loose Ospreys play allowed the Blues to steal possession, Willis Halaholo's kick through was brilliantly plucked from the air - and then juggled - by Gareth Anscombe, who sped over for the fifth try.

If ever a moment signified the difference in the two sides today it is Gareth Anscombe clutching the ball out of the grasp of Ospreys and Wales rival Sam Davies to collect a chip and score the Blues fifth try. 

Anscombe also converts. It’s turning into a rout. Who would have thought?!

That pressure tells as the Cardiff Blues attacking power tells with veteran prop Taufa’ao Filise powering over for the bonus point try.

Gareth Anscombe converts. The Ospreys are in disarray. Centre Josh Matavesi off for the Ospreys while Kieron Fonotia is on.

No changes at half-time. Cardiff Blues on top again as they go for the bonus point try.

We are back under way at the Principality Stadium.

Kick-off in the second half is soon approaching.

Image source, Huw Evans Picture Agency

One man not taking part in Judgement Day is this man.

Sam Warburton has been ruled out for the rest of the season after suffering a medial knee ligament injury for Cardiff Blues against Ulster last week.

The flanker is likely to be fit for the British and Irish Lions tour of New Zealand in June, however.

The Ospreys look dead and buried at half time, but Cardiff Blues fans, without a win against their rivals since 2010, probably aren't relaxing just yet. 

Remember the Superbowl? The Atlanta Falcons led 21-3 at half time. 

Who in the Ospreys line-up will assume the Tom Brady role? should the Ospreys embark on the ultimate rope-a-dope effort.

Image source, Huw Evans Picture Agency

In this fixture last season on Judgement Day IV, Ospreys fought from a 10-point deficit against Cardiff Blues to claim their 10th straight win against them.

Rhys Webb's late pair of tries sealed a stunning win for the Swansea-based region and effectively ended the Blues' hopes of qualifying for the European Champions Cup.

Alex Cuthbert returns to the field to ensure the Blues have their full quota of 15 as the Ospreys continue to pile on the pressure.

Another driving line-out is repelled by the Blues and that’s half-time. Ospreys will expect some stern words from Steve Tandy.

Ospreys turn down an easy kick at goal in front of the posts as they search for their first try against the 14 men of Cardiff Blues.

But the defiant Blues stem the tide and turn over possession before clearing their lines.

Dafydd Pritchard
BBC Sport Wales at the Principality Stadium

Cardiff Blues haven't beaten the Ospreys since 2010, and you would think this is their best opportunity for a while. 

The Ospreys look every bit a team who have lost their last three games, bereft without their talismanic lock and captain Alun Wyn Jones.

Their sloppiness has been ruthlessly exposed by the Blues, though they may have to hold on for the rest of the first half with Alex Cuthbert in the bin and the Ospreys near their try line.

Was this worthy of a yellow card?

Illtud Dafydd
BBC Radio Cymru

Wales coaches Robin McBryde and Shaun Edwards are spectators at the Principality Stadium, today.

A penny for their thoughts with just over half an hour played.

Which players are making a statement ahead of the tour to the Pacific Islands?

The Ospreys almost made their numerical advantage count when wing Keelan Giles pops up on opposite flank to feed Dafydd Howells. But Giles couldn’t quite hold onto the returning pass.

Cardiff Blues wing Alex Cuthbert is yellow-carded for a dangerous tackle on full-back Dan Evans when going up for a high ball.

Evans was taken out by Cuthbert in the air in what was more a clumsy challenge than anything deliberate. Blues will be down to 14 men for 10 minutes.

From the resulting scrum after Gareth Anscombe was denied, Cardiff Blues scored their third try. Number 8 Nick Williams powers over.

Anscombe converts. One-way traffic.