Heading into the final quarter of an hour against South Africa last November, Ireland looked good for victory.

The struggling Springboks trailed 14-3 and Joe Schmidt’s Autumn Series appeared to be getting off  to a solid, if unspectacular start, against the two-time world champions.

Then Jacob Stockdale announced his arrival on the scene. By the time referee Ben O'Keeffe blew the full-time whistle, the margin of victory was 35 points.

Three months previous he marked his debut against the United States with his now customary try, and Schmidt had placed enough trust in the Ulster man to award him his third start against a side who may not be the force they once were, but still were expected to pose challenges to an international rookie.

A shuddering man-and-ball tackle by Stockdale on Springbok winger Dillyn Leyds led to a turnover, from which Ireland immediately went on the attack. Minutes later and the home supporters got a taste of things to come from the 21-year-old.

Just inside the South African half, replacement Kieran Marmion spread the ball out right to Johnny Sexton.

Stockdale sprints past Springbok backrower Francois Louw

With the South African defence drifting, he popped the ball back inside to the onrushing Stockdale, who accelerated through the gap, burned one defender and drew another before slinging the ball out wide to Andrew Conway.

Fifteen seconds later and Rhys Ruddock crashed over to put the game beyond doubt. In the final minute he capped a fine home debut with a try of his own and his place in Joe Schmidt’s Six Nations plans began to take shape.

"It's not just about surviving in defence but starting to dominate"

He did slip off one tackle on Andries Coetzee, and the callow winger admitted post-match that it was an area of his game being addressed in camp.

"It's something that [Ireland defence coach] Andy Farrell has really helped me with. It's not just about surviving in defence but starting to dominate," he said.

"I feel like I'm starting to do that but, saying that, I've still a lot to learn."

He has continued to learn in defence, but is simply thriving in attack.

With 11 tries in nine games, he is averaging a try every 57 minutes in a green jersey. Wales and Italy in particular posed some difficulties for Stockdale as he continues to get his bearings at Test level, and even his intercept tries stemmed from defence.

The game clincher against Wales at the death was relief all around the stadium, but it was a gamble. Former international Shane Horgan said afterwards it was a gamble that wasn’t worth taking – Ireland had a slender three-point lead as Wales looked to execute a three-on-one overlap – but it paid off in spades.

A fortnight later and his intercept against the Scots was more calculated. Finn Russell’s long, floating pass allowed Stockdale in and set Ireland on their way. They never looked back to set up a Grand Slam finale at Twickenham

Not since Tommy Bowe has Ireland had an out-and-out finisher. His first try against Wales, and second against Scotland, were very similar; holding his width out wide and taking a swift pass to get in at the corner, checking inside the last defender against the Scots.

Against Italy he combined individual brilliance to run from inside his own half and evade two defenders with a simple trailing run from close range in a move straight off the training ground.

On the day of reckoning against England, he identified the space behind the cover defence, sprinted close to the tram line, chipped, out ran Mike Brown, controlled with his foot and got the vital touch before the end line. It owed as much to perseverance and attitude as skill, the hallmark of a Joe Schmidt player.

The head coach has put a lot of faith in the winger  - all his 11 caps have come as a starter and his withdrawal in Paris with five minutes remaining is the only occasion he has failed to finish – and 18 months out from the World Cup, will be hoping to have an even more rounded game by time Ireland head for Japan.

Time is on his side, but his record to date is quite remarkable.

Schmidt isn’t one to normally dole out too much praise individually for his players, but in the aftermath of the Grand Slam, was effusive in his praise for the try-scoring machine since his introduction to the squad.

"He’s been a bit of a revelation," he told RTÉ Radio One. "He is a young man that we were pretty keen to get him involved in November to see how he went because he is pretty raw, he’s very young.

"He’s a fine athlete and he’s getting more of an understanding of the game and making better decisions all the time."

That prospect bodes very well indeed for Ireland.