But as tantalizingly close as those teams are to deciding matters, there is plenty of unfinished business, and the American League Wild Card scrum remains the one race that has heads spinning all over the map. It's as tight as ever with six teams within 2 1/2 games of each other for the two available spots.
The Rays lead that race after a 4-3 thriller in 12 innings over the Rangers to break a tie, and Tampa Bay hopes it's a sign of more good things to come as the Rays seek some late-season momentum.
"I want to believe this game has to give us some kind of impetus moving forward," Rays manager Joe Maddon said.
There was heartbreak in Pittsburgh as profound as that walk-off elation in Tampa Bay, and those weren't the only places the final out was hard to secure. That meant free ball with huge implications, as four games with postseason hopes hanging in the balance went into extra innings, and a few others went down to the last strike.
Yes, just another day at the office for baseball's races, as the Pulse of the Postseason really got racing with 10 days remaining in the season.
This Wednesday on the job began with the type of game that would be copied several times -- leads exchanged, a blown save, extra innings.
With their quest for the AL West title ahead of last year's last-gasp pace but still unfulfilled, the A's went into extras at 4-4 following four two-run homers, two for each team. Josh Hamilton, who had a nightmarish series when the A's overtook the Rangers on the season's final day a year ago, boosted the Angels into extras with that last two-run homer, off A's closer Grant Balfour for his third blown save of the season, and then pushed them to a 5-4 victory over the A's with a sacrifice fly in the 11th.
From there, September scoreboard watching meant seeing a lot of tie games going into late innings, and tight finishes that had plenty of thrills.
The Yankees didn't go to extras, but they sure went to the limit -- Mariano Rivera eking out a four-out save after the Yankees scored four in the eighth and held on for a 4-3 victory over the Blue Jays.
They did it with Yankees with lesser pinstriped resumes, to be sure. Brendan Ryan, who won't even be eligible for the postseason roster because he was acquired after Aug. 31, got the Yankees' rally going with a ground-rule double, and Lyle Overbay, the veteran first baseman signed five days before the season began, contributed a sharp defensive play to help Rivera emerge with his 44th save of the season.
That was one of three games involving AL East teams in contention, and the other two went long into the night.
The Rangers and Rays were tied from the sixth inning on into extras with the AL Wild Card lead on the line. The Rangers struck first with a run in the 11th inning, but the Rays rallied against closer Joe Nathan to push it to 12, where they won on a Desmond Jennings walk-off single.
In Boston, the Orioles and Red Sox also went into extras after tying things up in the sixth inning. And when Chris Davis stepped up to the plate with the bases loaded, O's fans had to be dreaming of a grand slam. But none were disappointed the guy who has hit more bombs hit a 20-hopper through the infield for the go-ahead runs in what turned into a 5-3 victory.
"I'll take it any way I can get it," Davis said.
Strange things happen when the season is on the line, like a two-run rally for the Nationals that began with a single, had no other hits and got two Braves kicked out of the game. After a bases-loaded walk, Braves manager Fredi Gonzalez was shown the door by home-plate umpire C.B. Bucknor after arguing balls and strikes, and after the Nationals scored again on a sacrifice fly there went pitcher Evan Wood was ejected as he was being replaced.
But that seemed to wake up the Braves, who took the lead on a two-run homer by Justin Upton and took a 5-2 victory at Washington.
Strange things also happened in Kansas City, where the Royals held on against the Indians thanks in part to a rundown that started with Alex Gordon caught between first and second, transferred to third and home and ended up with Emilio Bonifacio scoring a run.
"It was like a snowball fight -- people throwing snowballs everywhere and everybody running around," Gordon said. "It worked out good for us."
In the end, it was one run that helped the Royals to a 7-2 victory, keeping the team's hopes for its first postseason appearance since 1985 very much intact.
Strange things happened in Pittsburgh as well, and in a gut-wrenching way for the fans at PNC Park.
The Pirates needed one last out when the Padres inserted Andrew Cashner -- the starting pitcher two days earlier with a one-hit gem -- as a pinch-runner at first base. His dive across home plate tied the game before the Padres wound up scoring again for what turned into a 3-2 victory.
The Pirates had taken the lead on an opposite-field homer by Andrew McCutchen in the sixth, but Mark Melancon's blown save in the ninth wound up being the difference.
"You hate for something like this to happen at this point. It hurts a little bit and it does tend to get magnified," McCutchen said. "But you've got to treat it like any other game. We have a lot more games left."
The Pirates wound up losing a game to both their division foes, with the Cardinals winning a 4-3 at Colorado -- Edward Mujica striking out Todd Helton with the bases loaded for the final out -- and the Reds hanging on in extra innings to beat the Astros, 6-5 in 13.
At the end of the night, the Dodgers were down by a single run heading into the bottom of the eighth but wound up taking a 9-4 loss to the D-backs that freezes their Magic Number for the division at two.
Also, the Mariners made for another concerning night of pitching for Tigers ace Justin Verlander in an 8-0 victory over Detroit, just the AL Central-leading Tigers' second loss in their last eight games.
With a wild Wednesday in the rearview mirror, the Pulse of the Postseason continues to beat Thursday with a slate of games that will keep the races rolling from daytime into the night.
The day will begin with what stands as the toughest test of the Pirates' joyful season, and the Dodgers and Red Sox will play with a postseason spot in reach by the time night falls.
After a crushing loss in the ninth inning Wednesday, the Pirates will go right back to the drawing board with the first game out of the chutes Thursday. Pittsburgh will be trying to avoid a four-game sweep when they send rookie Gerrit Cole to the mound to smooth out what has become a bit of a speed bump in their road to a first postseason spot in 20 years.
Their status in the NL Central race hangs in the balance -- a loss would drop them into a tie for second place in the division with the Reds, and therefore tied for the two Wild Card spots. The division-leading Cardinals will be wrapping up their four-game set at Colorado, holding a two-game lead for the first time since Aug. 15.
Even with a few teams getting a chance to catch their breath a little bit -- the Braves, Reds and Royals each getting the day off -- there will be plenty of tension to go around through Thursday's next day of the September stretch run.
In the AL Wild Card race, the Rangers and Rays go at it one more time at the Trop, the Indians take their quest home from Kansas City to meet the Astros, the Orioles and Red Sox square off one more time before the final three games of the season, and the Yankees finish off their series in Toronto.
The Dodgers' Magic Number to clinch the NL West remains at two heading into their finale at Arizona, and the Red Sox need either a win or an Indians loss to clinch a postseason spot.
Two AL division leaders will be trying to knock down their Magic Numbers from five as the Tigers finish off their four games with the Mariners and the A's start up a series against the Twins.
Elsewhere, the Nationals start up a series against the Marlins with a deficit of 5 1/2 games in the NL Wild Card race.
Thursday's key games to watch (all times ET)
Padres (Kennedy, 6-9) at Pirates (Cole, 8-7), 12:35 p.m. Preview >
Mariners (Paxton, 2-0) at Tigers (Cole, 8-7), 1:08 p.m. Preview >
Cardinals (Wacha, 3-1) at Rockies (Oswalt, 0-6), 3:10 p.m. Preview >
Dodgers (Nolasco, 13-10) at D-backs (Miley, 10-10), 3:40 p.m. Preview >
Astros (Keuchel, 6-9) at Indians (Jimenez, 12-9), 7:05 p.m. Preview >
Marlins (Alvarez, 4-4) at Nationals (Strasburg, 7-9), 7:05 p.m. Preview >
Yankees (Kuroda, 11-11) at Blue Jays (Redmond, 3-2), 7:07 p.m. Preview >
Orioles (Tillman, 16-6) at Red Sox (Lackey, 9-12), 7:10 p.m. Preview >
Rangers (Darvish, 12-9) at Rays (Moore, 15-3), 7:10 p.m. Preview >
Twins (Correia, 9-12) at Athletics (Straily, 10-7), 10:05 p.m. Preview >
If the postseason started today ...
Wild Card: Rangers at Rays
Division Series: Wild Card at Red Sox | Tigers at A's
Wild Card: Reds at Pirates
Division Series: Wild Card at Braves | Dodgers at Cardinals
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 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.
• Tiebreaker rules »
2013 postseason schedule
NL Wild Card Game: Oct. 1
AL Wild Card Game: Oct. 2
NL Division Series begin: Oct. 3
AL Division Series begin: Oct. 4
NL Championship Series begins: Oct. 11
AL Championship Series begins: Oct. 12
World Series begins: Oct. 23