David Sneyd reports from Aviva Stadium

WHAT IS IT they say about needing to be good in both penalty areas?

Thankfully the Republic of Ireland were absolutely lethal in each six-yard box.

Evan Ferguson’s powerful header on the stroke of half-time after being teed up by Mikey Johnston was an obvious blueprint for how Heimir Hallgrímsson can get more goals – and attacking joy – from this side.

And Caoimhín Kelleher’s penalty save from Joel Pohjanplo with a little under quarter of an hour remaining also shows the value of having an elite operator between the posts to get you out of trouble.

Ferguson was penalised when the referee was sent to the monitor by the VAR after his outstretched and high hand blocked the ball in the box.

Ireland made sure to keep Pohjanplo waiting even longer by opting to make a triple sub and by the time he stepped up there were just 13 minutes to go. Unlucky for some. Kelleher chose correctly with his dive – to his right – and was then up in a flash to collect the rebound at the left post.

He stayed down afterwards to buy a bit more time and kill some more seconds. When he sprung to his feet the crowd roared again as if it was his encore. Given his late error away to Greece last month that led to their second goal in a 2-0 defeat this would have felt even more enjoyable for the Liverpool man.

This was by no means a glamorous stage but victory at least alters the narrative around this team somewhat. Ireland still looked vulnerable and would have been likely punished by better sides but against a team of their own ilk they were able to find a way to come out on top. And not shoot themselves in the foot.

It wasn’t pretty and they were by no means dominant but in the moments that mattered Ireland were most effective. There were weaknesses that were shown up but none of the drastic lapses in concentration that have marred recent international windows.

Well before Kelleher’s dramatics, three minutes at the end of the first half showed just how delicate fortunes can be.

All of Ireland’s vulnerabilities through the middle were exposed by Finland when one pass around 40 yards from his own goal from centre back Arttu Hoskonen allowed Kaan Kairinen break towards the opposite end of the park.

Josh Cullen and Jason Knight had been completely taken out of the game after both springing forward in an earlier press.

Festy Ebosele rushed back from the right, sliding desperately to stop the attack by any means necessary, but the pass for Oliver Antman was swift. He used the overlap as a decoy, cut just inside the area and from a central possession struck a clever reverse shot that was set to wrong foot Caoimhin Kelleher.

Nathan Collins, though, anticipated the Finnish forward’s thinking and got a most important toe to the ball to deflect it onto the post before then gratefully heading clear for a corner.

It was the second time the visitors struck the woodwork, Robin Lod earlier curling an effort from just inside the box on the left off the opposite frame after Johnston had been too casual in possession and disposed by an aggressive tackle from Alho.

Those two same figures would again prove crucial just moments after Collins’ intervention when Ireland took the lead on 45 minutes.

This time it was the right back who was unable to come out on top in a one-one-one. He wasn’t swayed by the four step overs but once Johnston stopped and stuttered he got half yard to stand up a ball to the six-yard box. It was at this point that you could probably imagine everyone in a Finland jersey roaring the exact same thing as the exact same time – “pysäytä risti.” The literal translation according to Google is “stop the cross.”

Alho couldn’t and Johnston’s delivery was perfect. Ferguson powered into the air above the meek Robert Ivanov and Matti Peltola, and then guided the ball into an empty net.

It felt like an important moment for this Irish team because they were the ones to find a way to make the breakthrough in a game that was teetering on the brink. Sammie Szmodics was a threat in behind and, but for one mistimed run off the shoulder, would have opened the scoring earlier in the first half when he raced onto a pin-point Ferguson through ball.

That bit of link up play offered a glimpse into a potential partnership that could be mined for more magic, although their effectiveness waned as the game wore on and Ferguson was withdrawn in the break in play before the missed penalty.

Ireland are going to need to be a team that can do all of the dirty work with relish and zeal, and then produce quality.

And hopefully they won’t have to rely on similar Kelleher heroics to get over the line.

Victory now means Ireland go to Wembley to face England on Sunday in the knowledge that a promotion/relegation play-off awaits next March.

Hallgrímsson and his coaching staff embraced at the final whistle with a first home win secured. Those fans who booed and jeered after defeat to Greece here in September also seemed a bit happier as Ireland slowly strengthen their delicate confidence.