The Red Sox, long considered by some to be a World Series favorite and at the very least a shoo-in for a playoff berth, will regroup now, getting a Monday off day to think about things before diving right back into the schedule when a series against Toronto begins.
"You've got to panic at this point," Boston slugger David Ortiz said. "But you're not going to do anything panicking but playing better. Of course you're freaked out."
The Red Sox aren't the only ones.
The Atlanta Braves recently looked like a lock to get in via the National League Wild Card, but the St. Louis Cardinals aren't giving up, and on Sunday they beat the Braves, 6-3, to pull within 4 1/2 games in the Wild Card standings and within six of division-leading Milwaukee, which beat Philadelphia on Sunday.
"I feel like we are [in the race] if we keep winning," Cardinals manager Tony La Russa said. "It's exciting baseball. Guys have come through all over the roster. We've got a shot."
The Phillies' loss kept their magic number to clinch a playoff berth at two. They can secure a fifth consecutive postseason appearance with a win tonight in Houston and a Cardinals loss in Pittsburgh.
Meanwhile, the Texas Rangers can't be feeling too comfortable in the other very intriguing race right now, but they did manage to add a game to what had been a rapidly disappearing AL West lead over the Angels. The Rangers beat Oakland, 8-1, on Sunday, and the Angels lost to the Yankees, 6-5, so Texas' division lead is back up to 2 1/2.
"We just have to play our game," Rangers manager Ron Washington said. "Keep winning series, get an opportunity sometime to sweep some series, and we'll be all right. We're certainly not looking behind us, we're looking forward. They have to catch us, we don't have to catch them."
In beating the Angels, the Yankees moved a day closer to gaining home-field advantage throughout the postseason, holding on to the top seed in the AL and watching their closer, Mariano Rivera, notch career save No. 599. He can become the second closer to hit the 600 mark today in Seattle.
Elsewhere in the AL, Detroit rolled along, winning its ninth in a row by beating Minnesota, 2-1, on Sunday to increase its AL Central lead over the White Sox to 10 1/2 games and hold on to the second seed.
The other NL races showed a bit of movement, too -- enough to make an impact in the postseason seedings.
Division-wise, the D-backs didn't take too much of a hit by losing to San Diego while the Giants beat the Dodgers, because Arizona still holds an 8 1/2-game lead over San Francisco in the NL West. But with Arizona's loss and Milwaukee's win over the Phillies, the Brewers, who snapped a five-game losing streak, vaulted back over the D-backs for the second seed in the NL, meaning if the postseason began at this moment, Milwaukee would play the Braves instead of Philadelphia.
"I don't want to get to where we think where it is a 'must-win' game, but it was huge, it was a big game to win," Milwaukee manager Ron Roenicke said. "More, because it gets us in that right frame of mind. Hopefully we go on a roll again and start playing really good baseball."
The Phillies are still doing that despite a rare loss on Sunday. They still hold a 12-game lead on Atlanta and are cruising toward home-field advantage in the postseason.
If the postseason started today
Rangers (3) at Yankees (1)
Red Sox (Wild Card) at Tigers (2)
D-backs (3) at Phillies (1)
Braves (Wild Card) at Brewers (2)
Today's key games to watch
Cardinals (Lohse, 13-8) at Pirates (Lincoln, 1-2), 7:05 p.m. ET Preview
The Cards look to Comeback Player of the Year Kyle Lohse to keep the team's improbable comeback story going.
Rays (Niemann, 9-7) at Orioles (Britton, 9-9), 7:05 p.m. ET Preview
The Rays can't afford a letdown now that they're hitting the road in the midst of their late-season scramble to shock the Sox.
Marlins (Volstad, 5-12) at Braves (Beachy, 7-2), 7:10 p.m. ET Preview
Brandon Beachy's been impressive, and that will have to continue for Atlanta to stem the red Wild Card tide coming from St. Louis.
Phillies (Oswalt, 7-8) at Astros (Myers, 4-13), 8:05 p.m. ET Preview
The Phillies are resting easy with a huge division lead. Now they'll see how Roy Oswalt is shaping up for October.
Tigers (Porcello, 13-8) at White Sox (Danks, 6-1), 8:10 p.m. ET Preview
Rick Porcello can move the Tigers' Magic Number to six with a win over their closest pursuer.
Angels (Pineiro, 6-6) at A's (Gonzalez, 12-12), 10:05 p.m. ET Preview
The Angels need wins now. They also need Joel Pineiro to show something down the stretch.
D-backs (Saunders, 10-12) at Dodgers (Lilly, 9-13), 10:10 p.m. ET Preview
A road series against a division opponent is a good September test for a team that's setting up to be a big threat in the postseason.
Yankees (Hughes, 4-5) at Mariners (Hernandez, 14-11), 10:10 p.m. ET Preview
Facing Felix Hernandez on the road is not exactly an easy task for a team fighting for a division crown.
Padres (Harang, 13-5) at Giants (Surkamp, 1-0), 10:10 p.m. ET Preview
The defending World Series champions need victories in a hurry to see if they still have some of that 2010 magic left.
To calculate a team's magic number, take the number of games it has remaining on the schedule and add one. Then subtract the difference in the loss column between the team and its closest pursuer.
If two teams are tied atop the division and both are assured of making the postseason, head-to-head record would be used to determine which team is the division champ and which falls to the Wild Card.
If two teams are tied atop the division and share the Wild Card lead with another club, the ties will be broken in the following fashion:
The teams tied atop the division will play, with the winner taking the division.
The losing team will then play the remaining Wild Card contender, with the winner making the playoffs.
If three clubs are tied atop a division or Wild Card standings, each club would be designated in one of three slots, "A," "B," or "C." Clubs get to choose their designation based on head-to-head records. Tiebreaking games would then proceed like this:
Club A hosts Club B on Thursday, Sept. 29
The winner of the first game hosts Club C on Friday, Sept. 30, with the winner declared champion.
If two division winners are tied for the highest winning percentage, the following tie-breakers will be used to determine home-field advantage in the Division Series:
Highest winning percentage in intraleague games
Highest winning percentage in the last half of intraleague games
If the Clubs remain tied, then the tied Club with the higher winning percentage in the last half plus one of the intraleague games during the championship season. This process will be followed game-by-game until the tie is broken.
2011 Postseason schedule
American League Division Series: Sept. 30 - Oct. 6
National League Division Series: Oct. 1-7
American League Championship Series: Oct. 8-16
National League Championship Series: Oct. 9-17
World Series: Oct. 19-27
Full postseason schedule