SEATTLE (AP) -- If not getting better with age, Bartolo Colon is coming close to matching his best years.
Colon outpitched Felix Hernandez to reach 18 wins for the fifth time in his career, Brandon Moss hit a three-run homer in the first inning and the Oakland Athletics beat Seattle 6-2 Friday night to clinch home-field advantage for the AL division series starting next week.
Colon (18-6) became the first major leaguer in his 40s to win 18 games or more since Jamie Moyer was 21-7 for Seattle in 2003. The 2005 AL Cy Young Award winner allowed two runs and three hits for the AL West champions, including solo home runs by Franklin Gutierrez in the first and Kendrys Morales in the sixth.
''It's pretty phenomenal especially as consistent as he's been,'' Oakland manager Bob Melvin said. ''Eighteen wins, that's pretty phenomenal for anybody, let alone a 40-year-old.''
Colon's 2.65 ERA is second in the AL behind the 2.64 of Detroit's Anibal Sanchez, scheduled to start Saturday at Miami.
''He's unbelievable and he is very fun to play behind because it's strikes all day,'' Moss said.
Colon was suspended for the A's postseason run last season after testing positive for elevated testosterone. Colon thinks he could have boosted Oakland during its five-game loss to Detroit last October and is eager to pitch in the playoffs again.
''I can help the team a lot,'' Colon said through a translator.
Ryan Cook, Sean Doolittle and Grant Balfour completed the four-hitter. Coco Crisp went 4 for 5 with a run scored, his third four-hit game this year.
Oakland (95-65) remained two games back of Boston (97-63) with two games left in the race for best record in the AL and home-field advantage throughout the postseason.
''That's key. That's something we were really looking and hoping to do,'' Melvin said. ''We were able to do that today. We know we're going home. We know we're going to be home for a week, and that's a good thing.''
Hernandez (12-10) finished the season with his fewest wins since going 9-11 in 2008. The 2010 AL Cy Young Award winner gave up three runs and five hits in six innings with six strikeouts and a walk, retiring 13 of his final 14 batters.
''I needed to throw a lot more strikes,'' he said. ''I was all over the place the first two innings. After the third I was just trying to throw strikes and finish the hitters.''
Hernandez entered with 14 2-3 scoreless innings against the A's this season.
''He's tough. We've obviously had our struggles against him,'' Moss said. ''Most people do have trouble with him but tonight we were able to get to him early and give Bartolo some run support.''
With 216 strikeouts in 204 1-3 innings, Hernandez joined Randy Johnson as the only Mariners pitchers with five seasons with 200 innings and 200 strikeouts. Hernandez topped 200 innings for the sixth straight season and is the first major leaguers since Johan Santana (2004-08) with five consecutive seasons with 200 innings and 200 Ks. strikeouts.
The game marked the start of Eric Wedge's final weekend as manager of the Mariners. Wedge told his bosses he will not return for next season, saying it became obvious he did not have a future with the club.
''It's got to the point where it's painfully obvious to me that I just wasn't going to be able to move forward with this organization,'' he said before the game. ''We see things differently and we talked about it, but it just got to the point where I couldn't continue to move forward. Ultimately, I didn't feel like I could continue to manage here with the circumstances the way they are.''
Oakland boosted its lead to 5-2 in the seventh when Oliver Perez walked Josh Reddick on four pitches and pinch-hitter Derek Norris homered. Josh Donaldson added an RBI groundout against Carter Capps. Norris hit an RBI double in the eighth off Tom Wilhelmsen and scored on Daric Barton's single.
NOTES: Oakland OF Yoenis Cespedes left in the fourth inning with shoulder stiffness. He was playing in the field for the first time since Sept. 13. Manager Bob Melvin said Cespedes was day-to-day but there's a ''good chance'' he won't play Saturday. The injury had not affected Cespedes at the plate until Friday night when he aggravated it swinging. ... Norris became the fifth Oakland player with three or more pinch homers in a season, the first since Jeff Burroughs in 1982. He's 3 for 15 as a pinch hitter this year.