Defence was the big difference on Sunday morning in Yokohama in Ireland's 27-3 win against Scotland in their opening pool game.

Ireland dominated the tackle line for large parts of the game with an impressive line speed that put the Scottish attack under pressure on numerous occasions and forced them to turn the ball over.

Ireland did show vulnerability in that narrow defensive shape once or twice but the cover defence from Jonathan Sexton and Josh Van Der Flier made sure that Ireland didn't concede any tries throughout the 80 minutes. That is a great achievement against a side that prides themselves on their attack shape and variety.

Ireland did ship a few injuries because of the intensity that they brought to the defence.

They will have one eye on a quarter-final now and if they can afford not to risk one or two key players I think he will err on the side of caution.

Bundee Aki took himself out of the game with a big hit on Finn Russell and Peter O’Mahony went off for a suspected HIA as well. Both replacements in Chris Farrell and Jack Conan had huge impacts on the game which proves the strength in depth that has been spoken about with this Irish squad pre-tournament. Irish teams wouldn’t be used to losing players of that magnitude without being fearful of the consequences.

Sexton kicks against Scotland

Farrell was the catalyst for Ireland's third try. Andy Farrell will be happy with his defence turning a dangerous Scottish attack into a spilled ball in the tackle from Chris Farrell which gave Andrew Conway the chance to enter a foot race with Stuart Hogg. There aren’t many players around the world that would win that one but Conway did enough to stop Hogg over his own try line which gave Ireland the five metre scrum that they subsequently scored from, albeit with a bit of help from the post in the first place.

Scotland on the other hand made some very basic errors in defence. Henderson made the initial line break before James Ryan crossed the line for Ireland’s first try but the Scottish captain McInally was caught between two positions. Scotland didn’t set their foundation defence around the ruck which caused some uncertainty, allowing Henderson to use his power to go through the gap. Ireland finished the move with a few pick and go’s, the final one seeing James Ryan cross for the first try of the game.

Andrew Conway reaches for the line

Ireland created a few more opportunities in the first half. Scotland didn’t give themselves enough cover on the blindside of a left hand side scrum and Conor Murray put Jacob Stockdale into space. Stockdale showed his skills as the master of the chip and chase but the move broke down with a good counter ruck from the Scottish defence.

Once again, Scotland failed to set their foundation defence at the ruck. CJ Stander picked the ball and went through untouched but Ireland’s attack became laboured in the 22 and Scotland got out of jail again.

The rain came down at half time to add to Ireland's 16-point lead. It was already a tough task for Scotland to chase that lead but with the inferior pack in those conditions the game looked beyond them even from early in the second half. Ireland squeezed them with their pressure kicking game and waited for the mistake to occur.

It’s always much easier playing from the front because the opposition have to force their game a little bit more and you can live off their mistakes in a sense. Andrew Conway rose highest to disrupt Scotland after another contestable kick from Conor Murray. Conway did well to reload to his wing after Larmour won the ball and Ireland secured the ruck.

Tadhg Furlong touches down

Murray fed Conway out wide who had one defender to beat for his first try in the World Cup. Murray was very sharp all day and controlled the game superbly. His clearance kicks in the first half took the pressure off Ireland at vital times, he kicked his goals when Sexton was struggling a bit with his groin and he played others into the game around him. A fine performance from the scrum half but it is something that we got very used to in the past. Great to see him back to his best and at the right time for Schmidt.

Garry Ringrose was another guy who didn’t get much of the credit yesterday but he bossed his defensive channel very well when the likes of Hogg tried to inject a bit of pace into the Scottish attack looking for a spark. He had another great chop tackle in the wider channels that allowed Bundee Aki to win a turnover penalty earlier on in the game and had an all-round solid performance.

Jacob Stockdale on the break

It wasn’t a perfect performance from Ireland but they made Scotland look very average. It would be easy to say that Scotland were poor, and they were, but I think the credit has to go to Ireland for putting pressure on their attacking game and showing up their weaknesses in defence. It was a well-executed game plan from Schmidt and his players which now takes the pressure off them for the rest of the group.

Ireland might rest a few players going into the Japan game. Tadhg Furlong was getting treatment on his hamstring, Sexton had a groin issue, O’Mahony and Aki didn’t return to the pitch either. I’m not saying that we can take Japan lightly, they are sure to improve upon their first run out against Russia, but if Ireland can’t see that game through with the likes of Joey Carbery or Jack Carty, Farrell, Andrew Porter and Conan then we have bigger issues.

Schmidt may well go with his strongest team but they will have one eye on a quarter-final now and if they can afford not to risk one or two key players I think he will err on the side of caution.

It was a positive start to the tournament for Ireland and I think it will take the pressure off them. It’s time to build some momentum now and tick all the right boxes before a monstrous quarter-final in a few weeks’ time.

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