TOKYO -- Domingo Santana led an offensive barrage with an opposite field grand slam and the Seattle Mariners topped the Oakland Athletics 9-7 in the first game of the 2019 regular season in the Tokyo Dome.

A sellout crowd of 45,787 clamoring to see what is likely Ichiro Suzuki's final pro appearance in Japan was treated to an offensive showcase in the first of a two-game series. The Mariners and A's combined for 16 hits and five home runs, including a game-changing grand slam from Santana in his Mariners debut.

"Any time someone comes up with a big clutch hit, we score some runs, that's a huge deal," Mariners right-hander Marco Gonzales said. "You can see that once this team starts going, once we start firing it's kind of a domino effect. Seeing him get things going for us in a big way."

Santana inside-outed an 0-1 pitch, sneaking it inside the right-field foul pole to clear the bases and put Seattle on top 5-2 in the top of the third. The blast capped a five-run inning, and the Mariners would not relinquish the lead.

Khris Davis brought Oakland back within 5-4 on the first pitch he saw in the bottom of the third, blasting a line-drive, two-run home to left-center field. It was Oakland's second home run of the night after Stephen Piscotty opened the power show in the first inning.

The Mariners tacked on runs in the fourth and fifth innings. Tim Beckham crushed a two-run home run to left field the very next at-bat to eventually put Seattle ahead 9-4.

The bulb flashes of cameras started immediately when Ichiro walked to the on-deck circle in the top of the third. The crowd roared during his two plate appearances, and when he made his exit in the fourth inning, coming out with the position players only to turn around and return to the dugout. He was replaced by Daniel Vogelbach.

"Ichiro will play in the game tomorrow. Not sure if he will start but he will get out there at some point," manager Scott Servais said. "With Ichiro's situation coming into this series certainly wanted to give him an opportunity to play, but we also wanted to give other players an opportunity to get into the game and do what's best for the team."

Servais said the Mariners are going one day at a time deciding whether Ichiro would make the 25-man roster when the team returns to the U.S.

Matt Chapman brought Oakland back with a three-run home run, the game's fifth homer, in the seventh inning off of Nick Rumbelow to make it 9-7.

Hunter Strickland finished off the A's 1-2-3 in the bottom of the ninth, fanning Chapman to earn the save in his debut for the Mariners.

Mike Fiers took the loss for the A's. He lasted three innings in his debut as Oakland's opening day ace, pitching through Seattle's five-run third inning but not coming out for the fourth.

"It was not a good job by me," Fiers said of his outing and giving up a 2-1 lead on Santana's blast.

He faced only seven batters his first two innings and threw only 22 pitches, but faded in the third inning and was chased after 58 pitches.

Gonzales fared better on the other side in his debut as pitching staff ace for the Mariners, going six innings, giving up three earned runs, striking out four and walking one. He exited with the lead despite giving up runs each of the first three innings, but settling down and facing only 10 batters his final three frames.

--By Sean Kramer, Field Level Media