Tavis Knoyle makes a break for the Dragons but the move breaks down as his supporting team-mates knock the ball on.

Knoyle is one of only three players to have played for all four Welsh regions.

Can you name the other two? I'll give you until the end of this game. No Googling.

Big scrum for the Dragons, who earn a penalty and the chance to clear, which Sam Davies gladly accepts.

Ospreys were inches away from a try and, just a couple of minutes later, they find themselves back in their own half.

Referee Adam Jones is asking TMO Sean Brickell if Ospreys hooker Sam Parry made it over the line for his second try of the match.

Watching in real time, it looked like a try.

The replays of the big screen suggest it might be a tight call.

Jones and Brickell decide the ball was held up, so Ospreys will have a scrum five metres out from the Dragons try line.

Close to another try for the Ospreys.

Ashton Hewitt almost turns the ball over for the Dragons, but he just palms the ball into open play.

Rhys Webb picks it up and produces a flamboyant back-of-the-hand pass to find Kieran Williams, but he's tackled into touch just short of the Dragons' try line.

Ospreys are starting the second half as they started and finished the first: on the front foot.

They have a line-out near the Dragons 22 and their forwards take the direct route, up the jumper and into their opponents.

We're back under way for the second half, with Sam Davies kicking off for the Dragons.

While we take breath at the Liberty Stadium, here are the highlights of Scarlets' impressive win against the Cardiff Blues yesterday.

Gareth Griffiths
BBC Sport Wales at Liberty Stadium

Cardiff Blues head coach John Mulvihill said yesterday's defeat by Scarlets felt like a pre-season friendly.

This has been anything but. Four tries, a red card for George North and running rugby epitomised by a couple of flowing scores for front-rowers Sam Parry and Leon Brown.

Breathless stuff. I am still not sure about the crowd noise being pumped in around the Liberty Stadium though!

And that Sam Davies penalty is the final act of a thoroughly entertaining first half.

It's strange seeing Sam Davies playing without a scrum cap. The Dragons fly-half and captain has worn one throughout his career - but not today.

Anyway, Davies has just put over a penalty to reduce his team's deficit.

Ospreys are competing well despite their numerical disadvantage.

Rhys Webb plants an intelligent kick into the Dragons' 22 and the Ospreys will look to put the visitors under pressure from the line-out.

Wales head coach Wayne Pivac is here to run the rule over the Ospreys and Dragons players.

You'd think he's enjoyed what he's seen so far, save for George North's unfortunate red card.

A decent opening for the Ospreys, who shift the ball wide and set centre Kieran Williams on his way for a darting run into the Dragons' 22.

He can't quite get his offload away, Ospreys are penalised from the ensuing ruck and Dragons clear.

That Dragons lead didn't last long.

Stephen Myler, back on the field after a head injury assessment, slots over his second penalty of the match to nudge the Ospreys back in front.

Image source, Huw Evans Picture Agency

Justin Tipuric is a phenomenal player.

He is as skilful a forward as you're likely to see in world rugby, and he's also a master of the breakdown.

That's twice the Ospreys has forced a turnover in the past five minutes.

Wales centre Nick Tompkins is starting to see more of the ball as the Dragons get a foothold in this match.

Tompkins has joined the Gwent region on a season-long loan from Saracens.

Justin Tipuric immediately makes amends, forcing a turnover near his own try line just as Dragons were beginning to apply pressure.

Ospreys clear and Dragons will have a lineout just outside the home 22.

Excellent, even contest so far.

Another penalty for Dragons, this time for a high tackle from Justin Tipuric on Ross Moriarty.

Sam Davies takes it quickly and kicks to the corner.