The Japanese came on at half-time for Martin Petrov and, after taking a few minutes to settle in, set about giving Emmerson Boyce a tough time.
The could have even been a debut goal for the 19-year-old brought to Emirates Stadium straight from high school in Japan by Arsene Wenger, but a superb save from Ali Al-Habsi denied him.
It was a risky move by the Frenchman but he has seen it slowly pay off as Miyaichi has continued to develop his game after a loan spell at Feyenoord in Holland.
Ryo made a name for himself in the Eredivisie after a dozen blistering displays, scoring three goals and earning the nickname ‘Ryodinho’ for his dribbling skills.
This progression will be heartening to see for Gunners fans, who had been assured by Wenger that the Japan Under-17 international would be setting the Premier League alight at some point.
It is exciting to see a player’s reputation grow so much after a single half of football and, while it is sensible not to get too carried away, it is hard to deny that he is showing incredible potential.
His temporary boss, Owen Coyle, has been especially praising of Ryo’s attributes and predicted big things for him in the future.
Miyaichi’s greatest asset is his pace; he could most likely match any of the Premier League’s quickest stars, but also has the technical ability to do damage in the final third.
“Ryo has unbelievable ability, he has got pace to burn without wanting to warn opponents, he is lightning quick,” enthused Coyle in The Daily Mirror.
“He has also got great feet and is only going to get better. When he gets his chance he will show everybody what he can do.
“The proof will be in the pudding, but you will see what he has in his locker. He gets the ball and then something can happen.
“He is quite slight, so he has some developing to come. But his work-rate is similar to Chung Yong Lee.
“I also love his temperament, you always see him with a smile. I like his appetite for the game and his enthusiasm.”
This is high praise from the Scot and Miyaichi was obviously keen to prove him right when he joined in the loss to Wigan.
He possesses that exciting quality, which is rare in players, of having the knack of running at defenders and getting them turning towards their own goal.
His pace has a lot to do with this but it is the speed at which he can stop and cut inside to cross or shoot that makes him such a nuisance for full-backs.
Many are expecting to see more of Miyaichi and continual improvement over the rest of the season – including the player himself.
“I have to keep doing what I did against Wigan and hopefully I can get into the team from the start of matches,” he told Bolton’s official website.
“The manager told me to go and play my football and be confident. He wanted me to run at the defenders and take them on, so that was what I tried to do.
“I could have got a goal but the goalkeeper made a good save. If I had scored then everything would be more positive. Next time I'm sure I can score.”
Ryo’s comments suggest he is eager to get more playing time but has a calm head on his shoulders and is willing to wait and learn more about the stresses and strains of the Premier League.
It is interesting that, despite making such a notable impact on his league debut, Miyaichi’s progress has been largely unnoticed in the British press.
This just illustrates the pressure that young English players are under, as Alex Oxlade-Chamberlain has been talked about going to Euro 2012 when he is essentially just six months ahead of Ryo in his career progression at Arsenal.
You can argue that Oxlade-Chamberlain has not needed to go out on loan to break into the Arsenal first team, but he was brought up on a diet of tough League One football.
Ryo has said he wants to emulate the success of team-mate Jack Wilshere, who also had a half-season with the Trotters.
If Owen Coyle is to be believed, the Japanese teenager is well on his way to superstardom.