TOKYO -- While his boyhood hero was retiring from baseball, new Mariners southpaw Yusei Kikuchi merely went about retiring batters in an impressive Major League debut in Seattle's 5-4, 12-inning victory over the A's on Thursday as they swept the two-game Opening Series.

Ichiro Suzuki will get the headlines, but Kikuchi served notice of his own potential as the two Japanese stars, one departing and one just starting, made the Tokyo Dome their stage for the series finale and provided fitting drama for the sellout crowd in their homeland.

When Ichiro was taken out of the game in the bottom of the eighth to wild cheers from 46,451 fans, Kikuchi's tears streaming down his face in the Mariners' dugout spoke silent volumes.

Kikuchi said he's followed Ichiro's career since he was a third grader growing up in Japan.

"I took trains and buses to see his ball games," Kikuchi said. "Back then, he was a superhero for me. He was my idol. Every time I saw him, I was very nervous with butterflies in my heart and chest. It is the greatest gift for me to be able to spend time with him. I have learned a great deal from him, just looking at the way he practices and I'd like to make the best use of this experience throughout my career."

The 27-year-old Kikuchi looked outstanding for four scoreless innings before tiring in the fifth and giving up two runs -- one earned -- in his first start since signing with Seattle in January as a free agent.

Kikuchi allowed only two baserunners in the first four frames, on a walk and single, before giving up three hits in the fifth and being lifted when his pitch count reached 91. Kikuchi's second run crossed the plate after reliever Roenis Elias got a slow roller from Matt Chapman, but first baseman Jay Bruce dropped the throw on what would have been the third out.

Kikuchi pitched just about an hour away during his pro career in Japan and he certainly seemed at home on the Tokyo Dome mound, though he'd started just once there in his time with the Seibu Lions.

The Mariners continued relying on the long ball to provide early run support for Kikuchi, with a two-run homer by Ryon Healy in the second and a solo shot by Mitch Haniger in the third before the A's tied the game up in the seventh. The Mariners hit four homers in the two-game series and now head to Seattle, where they'll host the World Series champion Red Sox in their home opener next Thursday.

Ichiro, who announced his retirement after the game, helped out his young Japanese counterpart with several running catches in right field. Kikuchi waited at the top of the dugout to tap gloves with Ichiro and thank him after his running grab of a Chad Pinder drive to end the fourth.

Kikuchi said Ichiro's advice will ring in his ears throughout his career, which continues when he'll likely make his second start in the second game of the initial homestand against the Red Sox next Friday.

"The way he got himself ready, every day he was so earnest about his play," Kikuchi said. "I have read many books about him and seen programs. But the actual Ichiro was much more than that and I witnessed his resolve to play the ballgames and I was able to connect all the dots.

"When I was speaking with Ichiro, he encouraged me to perform well starting the very first year of my career. That will be the way to get recognized and he encouraged me to keep it up for three years. So I am going to hold on to those words and that will be my game starting next week. I will be ready."