That "business" begins with a pivotal four-game series in Baltimore that begins on Thursday night.
"When that place is sold out with Orioles fans, it's a great atmosphere," said O's first baseman Mark Reynolds. "I'm actually a little nervous out there playing in front of so many people. It's fun, I'm looking forward to it. This whole weekend should be a great time."
The Angels capitalized on the losses by Baltimore and Tampa Bay by beating Oakland, 7-1. Because all three teams ahead of them in the Wild Card race lost, the Halos now trail by just 2 1/2 games, thanks to their crucial sweep of Oakland.
"We needed it bad," said Angels righty Dan Haren, who picked up the win. "Coming in from Seattle, we knew we had to get all three."
The AL Central remained status quo with the White Sox a game up on the Tigers after both teams won on Wednesday. Tigers third baseman Miguel Cabrera hit a two-run homer, and he is beginning to establish himself as a legitimate Triple Crown threat.
Pittsburgh cut its deficit in the National League Wild Card race to 1 1/2 games with a 6-3 victory over Houston, coupled with the Cardinals falling to the Mets, 6-2.
The Dodgers are also 1 1/2 back after losing to the Padres, 4-3. They trail the Giants, who lost to the D-backs, by 4 1/2 games in the NL West.
Today's key games to watch (all times ET)
Rockies (Chacin, 2-4) at Braves (Hudson, 13-5), 12:10 p.m. Preview >
With the three teams chasing them for the No. 1 Wild Card spot all idle on Thursday, the Braves could pick up a half game with a win over Colorado.
Yankees (Phelps, 3-4) at Orioles (Hammel, 8-6), 7:05 p.m. Preview >
After reclaiming sole possession of first place, the Yankees head to Baltimore for the first game in a critical four-game set against the second-place O's.
If the postseason started today ...
Wildcard: A's (5) at Orioles (4)
Division Series: Yankees (2) at White Sox (3) | Rangers (1) at Wild Card winner
Wildcard: Cardinals (5) at Braves (4)
Division Series: Reds (2) at Giants (3) | Nationals (1) at Wild Card winner
A tiebreaker game 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
American League Championship Series: Oct. 13-21
National League Championship Series: Oct. 14-22
World Series: Oct. 24-Nov. 1