The Yankees took a 1 1/2-game edge over Baltimore, which split a doubleheader with Toronto. This is the first time since Sept. 2 their margin has been more than one game.
Curtis Granderson hit his 40th home run and Nick Swisher, Raul Ibanez and Eric Chavez also homered as New York won for the 10th time in 12 games.
Pettitte (5-3) hasn't given up a run in 11 innings since rejoining the rotation last week.
Swisher's two-out, two-run shot in the first inning off Liam Hendriks (1-8) made it 3-0.
ORIOLES 4, BLUE JAYS 1, 1ST GAME
BLUE JAYS 9, ORIOLES 5, 2ND GAME
BALTIMORE (AP) — J.P. Arencibia broke open a tight game with a seventh-inning grand slam, and the Toronto Blue Jays beat Baltimore to earn a doubleheader split and drop the Orioles 1 1/2 games out of first place in the AL East.
In the opener, Adam Jones went 4 for 4 with a homer to lead Baltimore. But the Orioles lost a half-game in the standings to the New York Yankees, who won 6-3 at Minnesota.
Arencibia, who came into the game mired in a 2-for-36 slump, had three hits and five RBIs. Edwin Encarnacion hit his 41st home run as Toronto ended a seven-game skid.
Ricky Romero (9-14) allowed four runs, eight hits and four walks in five-plus innings, yet stopped a 13-game losing streak over 15 starts since June 22.
Wei-Yin Chen (12-10) took the loss.
In the first game, rookie Steve Johnson (4-0) allowed three hits over five shutout innings to lower his ERA to 1.62. Jim Johnson, the fifth Baltimore pitcher, worked the ninth for his major league-best 48th save in 51 opportunities.
Henderson Alvarez (9-14) took the loss.
RANGERS 5, ATHLETICS 4
ARLINGTON, Texas (AP) — Adrian Beltre singled home the winning run in the ninth inning and the Texas Rangers rallied past Oakland, stretching their AL West lead over the Athletics to five games with nine to play.
The Athletics' lead for the second AL wild-card slot was cut to two games over the idle Los Angeles Angels. Oakland has lost six of eight.
Beltre, whose 35th homer tied the score in the seventh, grounded a sharp single through the middle of the infield off Tyson Ross (2-11) in the ninth, bringing home pinch-runner Craig Gentry.
The Rangers got the inning started with consecutive singles by Mitch Moreland and Ian Kinsler before Elvis Andrus' sacrifice bunt. Josh Hamilton, who had already hit his major league-best 43rd homer after missing the previous five games with a cornea issue, was intentionally walked to load the bases.
Joe Nathan (3-4) got the win.
WHITE SOX 5, INDIANS 4
CHICAGO (AP) — Adam Dunn homered twice, including a clutch three-run shot in the eighth inning, and the Chicago White Sox beat Cleveland to maintain their one-game lead in the AL Central.
Chicago snapped a five-game losing streak and stayed in front of second-place Detroit, which beat Kansas City 6-2. The top two teams in the division each have nine games left.
Dunn drove an 0-2 pitch from Vinnie Pestano (3-3) over the wall in right-centre with runners on the corners and two outs, putting Chicago ahead 5-3. Kevin Youkilis kept the inning alive with an infield single before Dunn connected for his 41st homer of the season. Dunn also went deep in the sixth.
Brett Myers (3-3) pitched the eighth for the win. Donnie Veal converted his first save opportunity of the season.
TIGERS 6, ROYALS 2
DETROIT (AP) — Justin Verlander breezed through eight innings and Prince Fielder hit a solo homer, helping the Detroit Tigers steady themselves with a win over Kansas City.
The Tigers remained one game behind Chicago in the AL Central.
Verlander (16-8) had little trouble with the Royals, who knocked him around for eight runs and 12 hits last month. He allowed two runs and nine hits this time, striking out eight without a walk.
Luke Hochevar (8-15) yielded six runs and 12 hits in 7 1-3 innings.