Heading into the day's action with a one-game lead over the Tigers in the AL Central, the White Sox were able to remain ahead thanks to a 5-4 comeback win over the Indians. Adam Dunn rescued Chicago from its sixth straight loss with a three-run home run in the eighth inning, his second of the game and 41st of the season.
"Tonight was Dunner's night," said White Sox starting pitcher Chris Sale, who finished with a no-decision after working seven innings and throwing 118 pitches. "He won the game for us, hands down."
Led by ace Justin Verlander, Detroit picked up a 6-2 win over the Royals to keep pace with Chicago. Verlander tossed eight innings, fanning eight and holding Kansas City to just two runs on nine hits for his 16th win of the season.
Meanwhile, the Yankees were able to get a little extra breathing room for the time being, picking up a 6-3 win over the Twins to increase their lead to 1 1/2 games in the AL East after the Orioles split their twin bill with the Blue Jays.
In his second start since coming off the disabled list, Andy Pettitte tossed six shutout innings and Curtis Granderson's 40th homer of the season was one of four hit by New York in the game.
"I love Andy Pettitte," said Nick Swisher, who hit a two-run homer in the first inning. "There's nothing that fazes him. He comes back, breaks his foot on a crazy play, has been itching to get back in the [rotation] for a long time, and once he does, he delivers -- every single time. You can only just look at that and be like, 'Man, I want to be like that.'"
Baltimore began the day with a 4-1 win over the Blue Jays to pull within one half-game of the Yankees behind a 4-for-4 performance from Adam Jones. However, the O's dropped the nightcap, 9-5, after Wei-Yin Chen couldn't make it past the fifth inning.
The Rangers were able to put more distance between themselves and the A's in the AL West thanks to a 5-4 win. Adrian Beltre smacked a bases-loaded single in the bottom of the ninth to give Texas a five-game lead in the division. However, it shrunk the A's lead for the second AL Wild Card spot to just two games over the Angels, who were idle on Monday.
"We're at the fun point of the season where every game is big," designated hitter Michael Young said. "That's the way it's going to be until the end of the season. This is the fun part. We have been spoiled by it the past couple of seasons and we want to keep it going."
The Cardinals were able to pad their lead for the second National League Wild Card spot, picking up a 6-1 victory over the Astros behind home runs from Pete Kozma and Yadier Molina and seven solid innings from Lance Lynn. Allowing just one run on five hits, Lynn picked up his 17th win of the season.
With the Brewers taking a 12-2 loss to the Nationals earlier in the day and the Dodgers having the day off, the Cardinals lead moved to 3 1/2 games up for that final playoff spot.
Tuesday's key games to watch (all times ET)
Indians (Kluber, 1-4) at White Sox (Liriano, 3-1), 2:10 p.m. Preview >
The White Sox hold a one-game lead over the Tigers in the AL Central with Francisco Liriano set to take the hill.
Royals (Chen, 11-12) at Tigers (Sanchez, 3-6), 7:05 p.m. Preview >
Anibal Sanchez will look to get the Tigers back-to-back wins as the team fights for its playoff life in the AL Central race with the White Sox.
Nationals (Lannan, 3-0) at Phillies (Hamels, 15-6), 7:05 p.m. Preview >
While the Phillies' chances at making the playoffs is growing slimmer, the Nats will look to get one step closer to clinching the NL East.
Blue Jays (Laffey, 3-6) at Orioles (Saunders, 2-2), 7:05 p.m. Preview >
The Orioles will look to cut into the Yankees' 1 1/2-game lead in the AL East after splitting a doubleheader with the Blue Jays on Monday.
Marlins (Eovaldi, 4-12) at Braves (Medlen, 9-1), 7:05 p.m. Preview >
Inching closer to a playoff berth, the Braves will send Kris Medlen to the hill. The Braves have won 21 straight games Medlen has started.
Brewers (Fiers, 9-8) at Reds (Cueto, 18-9), 7:10 p.m. Preview >
The Brewers are still clawing for a playoff spot, 3 1/2 games back of the Cardinals.
Rays (Price, 18-5) at Red Sox (Buchholz, 8-9), 7:10 p.m. Preview >
The Rays will send Cy Young candidate David Price to the hill. They sit three games back of the A's for that final playoff spot in the AL.
Pirates (Rodriguez, 11-13) at Mets (McHugh, 0-2), 7:10 p.m. Preview >
Falling out of playoff contention with a 6-2 loss to the Mets on Monday, the Pirates are 7 1/2 games back of the Cards for the second NL Wild Card spot.
A's (Milone, 13-10) at Rangers (Darvish, 16-9), 8:05 p.m. Preview >
After a tough 5-4 loss to Texas on Monday, the A's will look to get back on track as Tommy Milone takes the hill.
Cardinals (Garcia, 5-7) at Astros (Harrell, 10-10), 8:05 p.m. Preview >
Riding a three-game win streak into Tuesday's contest, the Cards hold a 3 1/2-game lead over the Dodgers and the Brewers for the second NL Wild Card spot.
Yankees (Hughes, 16-12) at Twins (Vasquez, 0-2), 8:10 p.m. Preview >
Doing their best to hold off the pesky O's in the AL East, the Yankees send Phil Hughes to the mound.
Mariners (Ramirez, 1-2) at Angels (Greinke, 14-5), 10:05 p.m. Preview >
Just two games back of the A's for that second AL Wild Card spot, the Angels turn to Zack Greinke for a much-needed win.
Dodgers (Beckett, 6-13) at Padres (Volquez, 10-11), 10:05 p.m. Preview >
The Dodgers send Josh Beckett to the hill as they look to make up ground on the Cards for that second NL Wild Card spot.
D-backs (Collmenter, 4-3) at Giants (Lincecum, 10-14), 10:15 p.m. Preview >
On an extra day of rest, Tim Lincecum gets the nod for the Giants as they try and stay hot heading into the playoffs.
If the postseason started today ...
Wild Card: A's at Orioles
Division Series: Yankees vs. White Sox | Rangers vs. Wild Card winner
Wild Card: Cardinals at Braves
Division Series: Reds vs. Giants | Nationals at Wild Card winner
For the 2012 postseason, the team with the better record will play the first two games on the road to start the Division Series.
To calculate a team's magic number, take the number of games it has remaining and add one. Then subtract the difference in the number of losses between that team and its closest pursuer.
A tiebreaker games will be played to determine a division winner, even if the tied clubs are assured of participating in the postseason. If a division championship tiebreaker is necessary, the head-to-head record between the clubs will determine home-field advantage. If the head-to-head record is tied, then division record will be the next tiebreaker.
If two clubs are tied for the two Wild Card berths, home-field advantage will be determined by the head- to-head record between the clubs. If the head-to-head record is tied, then division record will be the next tiebreaker.
2012 postseason schedule
Wild Card playoff games: Oct. 5
Division Series: Oct. 6-12
AL Championship Series: Oct. 13-21
NL Championship Series: Oct. 14-22
World Series: Oct. 24-Nov. 1
Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.