Ryo Miyaichi scored in his homecoming to highlight Arsenal’s comfortable 3-1 victory over Nagoya Grampus on Monday.

The Japan winger struck from the spot midway through the opening half for Arsenal, which also had goals from Olivier Giroud and Theo Walcott. Kisho Yano netted a consolation in the 72nd minute for Nagoya.

The master proved he still had lessons for the student as Arsene Wenger’s side outclassed Grampus, coached by the Frenchman’s former star player at Nagoya during the mid-1990s, Dragan Stojkovic.

It didn’t take long for Arsenal to reach the scoreboard as Giroud found the net in the third minute on a muggy evening before a crowd of 42,919 at Toyota Stadium — a record turnout at the venue.

The French striker was picked out by Tomas Rosicky, who flighted a cross from the right wing. Completely unmarked, Giroud nodded past goalkeeper Seigo Narazaki with ease to give the Gunners the lead.

It was difficult to tell which side was in preseason as Nagoya, currently 12th in the J. League halfway through the campaign, looked sluggish throughout the affair.

Apart from Yano’s goal and a couple of chances late in the first half, both wasted spectacularly by Yoshizumi Ogawa, Grampus couldn’t create and did not seem particularly inspired.

Arsenal made it 2-0 in the 26th minute through hometown favorite Miyaichi, who was nudged into taking the penalty by captain Mikel Arteta after a late lunge by Marcus Tulio Tanaka earned the visitors the spot kick.

Miyaichi, who took a seat on the bench at halftime, converted with authority, blasting into the bottom corner to the delight of the crowd.

Five minutes to the hour. Walcott delivered Arsenal’s third — a soft close-range chip over Narazaki — just moments after he was foiled by the Grampus custodian in a one-on-one.