Oakland clinched its second straight AL West title on Tuesday and will face Boston in the first round of the playoffs.
Zito, who won the AL Cy Young award in 2002, will figure heavily in how far the A’s advance in the postseason.
Despite a career-high 12 losses, Zito has been superb in September. He has wins in each of his last three starts, posting a 1.27 ERA over that span.
The left-hander is 6-2 with a 3.55 ERA in 10 career starts against Seattle, which has won the last three season series against Oakland. The Mariners lead this year’s series 10-7.
Edgar Martinez, the Mariners’ 40-year-old designated hitter, got a standing ovation when he batted in the eighth inning. He will decide this winter whether to return for next season or retire.
Martinez has a .315 batting average with 297 home runs and 1,198 RBIs in 17 major league seasons, all of them with Seattle.
Despite two errors on Friday, the Mariners have only 63 for the season and can set a record for the fewest errors in the major leagues in a season in their final two games. The 1999 New York Mets hold the record with 68 errors.
STANDINGS: Athletics - 1st place, AL West. Mariners - 2nd place, 5 GB, AL West.
ATHLETICS PROBABLE STARTER: Zito (14-12, 3.22 ERA). Zito pitched six innings, allowing one unearned run and three hits to earn a 7-3 win over the Texas Rangers on Monday.
MARINERS PROBABLE STARTER: Ryan Franklin (10-13, 3.50 ERA). Franklin has held opponents to two runs or fewer in each of his last five starts. The right-hander held the A’s to one run and four hits in eight innings to lead the Mariners to a 6-1 win on Sept. 19. Franklin is 1-2 with a 1.45 ERA in September.
OFFENSIVE LEADERS: Athletics - Eric Chavez, .280 avg. and 28 HRs; Miguel Tejada, 106 RBIs and 96 runs; Tejada and Eric Byrnes, 10 SBs. Mariners - Suzuki, .312 avg., 110 runs and 33 SBs; Bret Boone, 34 HRs and 114 RBIs.
SEASON SERIES: Mariners, 10-7.
STREAKS AND NOTES: Athletics - OF Jermaine Dye is 0-for-10 with four strikeouts lifetime against Franklin. … RHP Keith Foulke leads the AL with 43 saves. … SS Tejada is batting .326 since the All-Star break. Mariners - 1B John Olerud is batting .400 (8-for-20) in his career against Zito. … The Mariners have hit only 137 homers this season, 13th in the league. Only Tampa Bay, with 136, has fewer. … OF Suzuki ranks second in the AL with 209 hits.
ROAD/HOME RECORDS: Athletics - 39-40 on the road; Mariners - 48-31 at home.
INJURIES: Athletics - LHP Mark Mulder (leg), 15-day DL; LHP Micah Bowie (elbow), 60-day DL. Mariners - IF Greg Colbrunn (wrist), 15-day DL; RHP Rett Johnson (shoulder), 15-day DL; LHP Matt Thornton (elbow), 60-day DL.