Josh Hamilton dropped a fly ball in centre field for a two-run error that put the A's (94-68) ahead 7-5 in a six-run fourth inning.
While Hamilton's Rangers (93-69) are headed to the new one-game, wild-card playoff, the A's get some time off before opening the division series in their first post-season appearance since 2006.
The A's needed a sweep Texas and they delivered to win their first division crown in six years and 15th in all. They overcame a five-game deficit in the final nine days and took sole possession of the West's top spot for the first time this year.
Oakland's Coco Crisp hit a tying two-run double in the fourth against Derek Holland (12-7). Brandon Moss drove in three runs, including a two-run single in a four-run eighth.
Rookie Evan Scribner (2-0) allowed two hits and struck out two in three scoreless innings after replacing struggling starter A.J. Griffin.
Derek Norris homered leading off the eighth with his seventh homer and Oakland's major league-leading 112th since the All-Star break.
YANKEES 14, RED SOX 2
NEW YORK (AP) — Robinson Cano and Curtis Granderson each hit a pair of homers, powering the Yankees past the Red Sox for their 13th AL East title in 17 years.
In front of fans poised to party from the first pitch, the Yankees completed a three-game sweep of the last-place Red Sox to win their second consecutive division crown. The championship was locked up by the seventh inning, when Baltimore's 4-1 loss at Tampa bay went final.
Cano tied a career high with six RBIs as New York secured home-field advantage throughout the AL playoffs. The Yankees will open on the road Sunday against the winner of Friday's wild-card game between Baltimore and Texas.
RAYS 4, ORIOLES 1
ST. PETERSBURG, Fla. (AP) — Evan Longoria homered three times and the Rays beat Baltimore, ending the Orioles' bid to force a one-game tiebreaker for the AL East title.
The loss left the Orioles as a wild-card team. They'll play Friday at Texas, with the winner advancing to the division series.
Longoria finished the season with a bang for the second straight year, hitting solo shots off Chris Tillman in the first and fourth innings and adding another solo shot off Jake Arrieta in the sixth.
With a chance to tie the major league record, Longoria grounded out in the eighth.
TIGERS 1, ROYALS 0
KANSAS CITY, Mo. (AP) — Miguel Cabrera became the first player in 45 years to achieve the Triple Crown in the AL Central-champion Tigers' victory over the Royals.
Cabrera went 0 for 2 with a strikeout, then left in the fourth inning of the regular-season finale. He received a standing ovation from the opposing fans.
He finished with an American League-leading .330 average, 44 homers and 139 RBIs, becoming just the 15th player to achieve the milestone and the first since Boston's Carl Yastrzemski in 1967.
Max Scherzer pitched four innings for Detroit to test his sore right shoulder ahead of the playoffs, which the Tigers will open Saturday at home against Oakland. The bullpen took over from there, with Luis Marte (1-0) picking up the win and Luke Putkonen his first career save.
Austin Jackson drove in the only run off Royals starter Luis Mendoza (8-10).
WHITE SOX 9, INDIANS 0
CLEVELAND (AP) — Dan Johnson hit his first three homers of the season and Chicago added two more in the game as the White Sox routed the Indians.
Gavin Floyd (12-11) gave up three hits over seven innings. He struck out six, one short of getting 145 strikeouts for the fifth straight season despite being on the disabled list twice this year.
Johnson hit two two-run homers off David Huff (3-1). His 424-foot shot in the second inning was his first in more than a year. His second made it 7-0 in the fifth, two batters after Paul Konerko hit his 26th of the season.
BLUE JAYS 2, TWINS 1
TORONTO (AP) — Brandon Morrow struck out a season-high 11, Omar Vizquel wrapped up his 24-year career and the Blue Jays beat the Twins to complete a three-game sweep.
Morrow (10-7) allowed one run and three hits in eight innings, his longest outing since a complete game victory at Chicago on June 6. Toronto's staff leader in wins, the right-hander reached double digits in victories for the third straight season.
Brandon Lyon finished the ninth for his first save as the Blue Jays avoided 90 losses, finishing at 73-89. They finished at .500 last season.
Mike McCoy replaced Vizquel with two outs in the ninth and the veteran infielder left to a standing ovation, hugging his teammates, doffing his cap and tapping his heart to show his appreciation.
MARINERS 12, ANGELS 0
SEATTLE (AP) — Casper Wells tied a career-high with five RBIs including a three-run homer in Seattle's six-run seventh inning, and the Mariners routed the Angels.
Angels' star rookie Mike Trout went 2-for-3 at the plate with a double leading off the sixth and a single in the eighth to finish the season with a .326 average. That was good for second in the AL batting race, but pretty much locked up the Triple Crown for Detroit's Miguel Cabrera.
Angels' starter Jered Weaver pitched just one inning before leaving the game. Weaver (20-5) had a chance to become the fourth pitcher in Angels' history to reach 21 wins, but called it a season early after giving up two runs, two hits and walking two batters in the first inning. The team said Weaver had "general fatigue" as the reason he threw just one inning.