Few players have ever announced themselves to the rugby world with a performance as emphatic or as electrifying as the one Ruaridh Jackson delivered on his Heineken Cup debut for Glasgow against Bath five years ago.

A star was born in those 80 minutes, as the tyro fly-half shimmered and swerved across the Recreation Ground and into the sport's consciousness, embroidering his performance with a dramatic interception try. The new messiah of razzle-dazzle rugby had arrived.

Yet the fact that Glasgow lost the game 35-31 should have set off a few alarm bells. It certainly did for Jackson, for it taught him at the outset that rugby is not a game of how, but of how much. Over the next few years, his career sometimes seemed to be a battle to reconcile those two things. On Saturday, though, he finally seemed to get it right.

With Tim Swinson winning the man-of-the-match award and Tommy Seymour collecting his brace of tries, Jackson rather slid under the radar against Japan. But it is worth replaying the video just to see how many good things he did - and, just as importantly at this level, to see how few mistakes he made. He had one gruesome defensive lapse in the build-up to Japan's first try, but otherwise his was a performance of maturity and assurance. Grown-up rugby from a player who, in some eyes, will always be the new kid on the block. It was also a game in which he repaid a debt he owed to Seymour. Five months ago, Jackson had squandered the chance of a Scotland try when he threw what should have been a scoring pass high over the head of his winger. On Saturday, he got it right, twice, as he put Seymour through for both his scores.

And his reward? With 15 minutes left on the clock Jackson was withdrawn, Duncan Weir taking his place. And with 13 minute on the clock Weir took advantage of an error by Japan centre Craig Wing to gather the ball and score his first try for Scotland. As Jackson has never got himself over the whitewash in 22 matches, he had every right to feel miffed by that sequence of events.

Jackson has acquired a raffish look since sprouting his Movember moustache, and seemed genuinely pleased for his Glasgow clubmate. "It's brilliant for Duncie," said the man who had every right to find a cat to kick at that point. "You saw the excitement from him. I've never seen him pop up off the deck quite so quickly. It's great for him and I'm really happy for him."

In fact, Jackson was just as happy to spread the love to Seymour as well, having harboured a certain guilt since his error against South Africa in June. And a certain determination as well, for in that match in Nelspruit Scotland surrendered a 17-6 lead before going down 30-17, and there is a sense of unfinished business in the camp ahead of the return game on Sunday.

"The boys were bitterly disappointed after the Nelspruit game," Jackson said. "We can use that for a bit of motivation. We will be at home and want to win all our games at home. We want to put in a good performance for the crowd and make the nation proud, and to do that it is going to take a huge effort."

So did starting the autumn with one win make the prospect of claiming another any likelier? On that front, he was more circumspect.

Jackson said: "It takes a bit of pressure off, I guess, and gives a good momentum. But we are under no illusion about the next test. South Africa have been in brilliant form and it will be extremely tough. I expect it will be more physical and they won't keep the ball in hand as much as Japan. Japan ran it from everywhere and really stretched our defence. It was a good test for us, but we know we will need to alter things and it will be a tough week ahead."