The referee’s decision to award Leigh Halfpenny a penalty as the clock ticked red denied Leinster the chance to sneak out of Wales with a win for the second weekend in a row.

It was a marginal call in a tight game between the two teams that will dominate the pool this year, just as they did last year.

Halfpenny had only one hand on the ball after Luke McGrath hit the deck, hardly what I’d call latching on. But the ruck was late, so maybe the ref had the right to call it.

It ended a fightback from Leinster that did not look on the cards at seventy minutes when the boys in blue drifted 27-14 behind after a series of uncharacteristic loose plays.

The game had been back and forth all night with the Scarlets opening the brightest, forcing repeated infringements from Leinster on their own goal line and eventually the yellow carding of Josh Murphy.

Although they survived the initial onslaught from the Scarlets, they simply could not clear their lines, despite several opportunities from defensive scrums. Gibson-Park passed to a seemingly unprepared Byrne, fluffed the kick, giving the men in red a dangerous line-out in the twenty two.

In a night of periodic rain, both sides used the driving maul to good effect. Scarlets tasted the first blood; their maul was illegally collapsed but during the ensuing advantage period Ken Owens barrelled over.

The TMO paused the kick. It sort of looked like there was a hand underneath. One suspects that if the ref had asked for a decision instead of immediately awarding the try, then this would not have been given. The question put to the TMO was “is there any reason I cannot award the try?”, and the evidence was not clear enough. Scarlets took the deserved seven point lead.

It took Leinster a long time to get into the match. Ross Byrne, who put in some huge defensive tackles during the game missed his first chance for posts. A strange miss considering he hit a few conversions from the touch lines.

During the first twenty minutes there were multiple, uncharacteristic holes in Leinster’s defensive lines. The Scarlets did not seem to be doing anything more than running straight crash ball lines, but kept getting through.

The magic kicked in eventually, Larmour and Lowe interchanging passes before the last pass to O’Laughlin was called forward by the assistant referee. The pace Leinster were playing at had increased and the began to draw some penalties.

The maul was the best choice attack as rain began to come down, heavy enough to be blamed for a lot of dropped balls. When Leinster mauled from their own ten meter line to their opponents, the Scarlets were reeling. The backs got in on the action, O’Laughlin’s looping pass to McFadden notable, and the winger side-stepped the cover to dot down. Byrne levelled with a tough kick.

There were mistakes by both sides, the worst, Gibson-Park’s box kick directly into touch. The game swung back and forth, kicking became key, and the Scarlets moved into blue territory. A high tackle from Ruddock gave them an easy shot at goal to got 10-7 ahead with five minutes of the half remaining.

We had a chance with a nice move of the line out, but Ruddock was adjudged to have knocked on; the replay showed it was the tackler’s hand ripping the ball. Ah well.

But from the scrum, Davies made a mess of things, ran into trouble and threw a wild pass. A red hand picked up the knock giving the softest of penalties to Leinster, perhaps karma getting involved. Kick to the corner.

Another fine maul that should have resulted in a try was ruined at the last moment. Cronin had the ball but it appeared to come loose as he was diving to the ground. The TMO called no try. However, the ref had already signalled that he would give a yellow card for the infringement in the maul.

We had time for more action as the clock kicked down. The Scarlets looked rattled now, and Ruddock knew it. He ordered Byrne to kick to the corner again despite there being only seconds left on the clock. The line out was not as smooth this time and no maul ensued. But we had the ball and were camped on their line, giving the half some symmetry.

This pressure paid off; another penalty was given, this one close to the posts. What would Ruddock do now as the clock ticked out? He asked for a scrum.

It can be difficult to read Leo Cullen’s mood, he has a poker face at all times when working. But I’d call his pose pensive, as he stood out of the dugout in the rain gazing at the action. A sure three points to go in one behind traded for a chance at a score.

Ruddock made the right choice. The prop was in the bin, so a substitute was required to make the scrum regulation. The defensive outfield looked bare. The try was training ground stuff; Gibson-Park to Byrne to Lowe and touch down in the corner, with a touchline kick nailed by Byrne. Leinster go in the break with a skip in their step. And the lead: 10-14.

The one blight on the score was the messy, late hit on Lowe, who reacted angrily to the attention. I fully agree with Tony Wards Wish List article for this coming rugby season. Number four called out this sort of negative play.

The second half seemed to have a lot more kicking. Both teams played for territory. Leinster, unfortunately, stayed ahead in the penalty count and the Scarlets clawed their way back in with Halfpenny penalties in minute 50 and 63.

There followed a crazy period lasting just under ten minutes where everything went to pot that Leinster did. Messy line outs, missed tackles, and tacking a player out in the air at line out.

It might be attributed to the substitutes that came pouring on, the Leinster front row being changed entirely and Tomane making his second appearance. They did gel, but not before letting the Scarlets score a soft enough try.

From a knock on by Nagle as he tried to barge out of his own twenty-two, the men in red quickly turned defense into attack. Leinster were not in position and some nice interplay by the Scarlets allowed Gareth Davies to touch down under the posts.

At nine points down, only ten minutes on the clock and Scarlets taking control, I wrote the note “Not impossible but looking bleak.” The final ten minutes were a roller coaster ride.

First off Henshaw looked like he might be in danger from the ref as he collided with Halfpenny in the air. Mike Adamson believed that there was fair competition in the air.

Leinster started to get their hands on the ball though, and big runs from Tomane and Dooley got us to spitting distance from the line. The pressure was immense and Ruddock get the score. Blues are back in the game at 23-21.

There was a bit of a comedy interlude with Gareth Davies claiming that the scoreboard was wrong, that Scarlets should be on 24 points. The ref said dryly, “We’ll take a look.”

The ref was likeable enough, making some good, crisp decisions and communicated well with the teams. His line “he can’t have gone to his knees again, he just came on” shutting up the noisy red pack. There’s something to be said to immediately penalise teams that talk to the ref (apart from the captain). First offense a free kick, then a penalty, then a warning and a penalty, and the yellow cards all the way. The ref had earlier asked Ross Byrne to move his penalty back to the correct place “to keep the crowd off his back” with a laugh; ref humour.

Anyway, Leinster lost the grip for a while and didn’t get it back until it was nearly too late. They squandered the restart and most of the five remaining minutes as the Scarlets played up the jumper rugby and looked like they might see out the game in that manner.

The blue defensive line held firm and eventually we got the ball back from the tiring Scarlets. Then the excitement got to fever pitch as the boys in blue made solid, consistent progress up the pitch.

It all ended when Luke McGrath’s snipe near the touchline was cut down and Halfpenny made his timely intervention. Just enough doubt to win the penalty. Game over. We outscored them in tries, but the two missed penalties will have caused Ross Byrne a few nightmares last night.