Suzuki reached the milestone on a double in the first inning against Gio Gonzalez (5-5), who went a career-high seven innings, allowing two runs on six hits.
"I was very clueless to what happened," Gonzalez said. "He's the first batter, I tried to go inside and he gets a leadoff hit. He did his job and I congratulate him."
Hairston popped up with the bases loaded in the fifth inning against Seattle starter Doug Fister. When he found himself in the same situation two innings later, he delivered.
"He's been struggling lately but the ball jumps off his bat," A's manager Bob Geren said. "He's getting a chance to play every day and he'll only keep getting better."
Hairston made an impression on Geren when he homered twice in a spring training game.
"It was kind of our introduction to him," said Geren. "It was 'Wow, who is that?' Little did we know then he'd be with us a few months later."
Landon Powell also homered for the A's, who won their second straight.
Jose Lopez and Adrian Beltre drove in runs for the Mariners, who had won nine of their previous 13 and seemed on their way in this one before Hairston's slam off Scott Kelley (4-2).
Fister lasted five innings, giving up a run on six hits before leaving after developing a blister.
"He developed it about the third inning and he did a good job of getting through five," Mariners' manager Don Wakamatsu said. "It's unfortunate because from the beginning it looked he was going to pitch a heck of a game."
Brad Ziegler pitched the eighth and Andrew Bailey got the final three outs for his 23rd save in 27 chances, including the last 18 in a row.
Suzuki, who has a 17-game hitting streak against the A's, drilled Gonzalez's second pitch down the right field line for a double and hit No. 2,000.
"No matter what the situation is I want to get a hit as early as possible," Suzuki said through an interpreter. "Personally it's not a big surprise, but looking back to my first spring training when I was criticized, it does have meaning now."
The Mariners' outfielder, who accumulated 1,278 hits in Japan, became the second-fastest to 2,000 hits, recording it in his 1,402 major-league game. Al Simmons did it in game 1,390.
"I knew he could play baseball and he's just fun to watch," Mariners' outfielder Ken Griffey Jr. said. "That's a special day for him and for all of us. It's nice to see history made. Five more hits and we get to watch it all over again."
Even before the ball fell in front of the Seattle bullpen, fans stood to cheer Ichiro, who led off a game with a hit for the 215th time.
"He's a special player," Wakamatsu said. "He'll continue to tack on record after record as long as he stays healthy."
Suzuki has 128 hits in Oakland, his favorite road park. His 227 hits against the A's is his second most behind the 239 he's earned against the Texas Rangers.
Suzuki, the 259th player to reach the milestone, went 1 for 4 and needs five more hits for 200 on the season, which would break the record he shares with Willie Keeler at nine consecutive seasons with 200.
Mariners' OF Franklin Gutierrez recorded his AL-leading 12th sacrifice bunt. ... The Mariners have scored in the first or second inning in nine of their past 13 games. ... Gonzalez allowed 31 runs in his first 34 innings at home. ... Bailey tied Oakland's rookie record for saves, matching Huston Street with his 23rd.Sign up for breaking news alerts from FOXSports.com!