At the start of the day, six teams were in danger of seeing their seasons end. The entire season potentially came down to a single game, or better yet, four single games.
In the end, two teams were sent packing and four were left preparing for do-or-die Game 5s on Friday. For the first time in the Wild Card era, all four League Division Series matchups went the distance, giving fans the maximum 20 possible LDS games.
National League DS Game 5: Giants 6, Reds 4
The Giants opened the slate by completing a historic comeback and advancing to the NL Championship Series. With the win, San Francisco became the first NL team in the Wild Card era to win a Division Series after losing the first two games.
Making the feat all the more impressive is that the Giants' three straight victories all came on the road thanks to the new 2-3 format. That was an accomplishment all by itself, considering the Reds hadn't lost three straight at home at any point this season.
The must-win contest started slow, with four scoreless innings, before the Giants jumped all over Reds starter Mat Latos in the fifth. San Francisco struck for six runs, capped by a Buster Posey grand slam that knocked Latos out of the game.
Cincinnati responded in the bottom of the inning with a two-run double by Brandon Phillips that started a comeback attempt. Ryan Ludwick added a solo homer in the sixth to pull the Reds within three runs, setting the stage for one final push in the ninth inning.
With two on and one out, Ludwick drove in another run with a single that cut the Giants' lead to two runs. Closer Sergio Romo wouldn't let the Reds get any closer, though, forcing Jay Bruce into a flyout to left field and striking out Scott Rolen to end Cincinnati's season.
So to kick things off, the NL West champion Giants finished their comeback by eliminating the NL Central champion Reds.
NLDS Game 4: Nationals 2, Cardinals 1
Coming off back-to-back blowout victories in Games 2 and 3, the Cardinals had the chance to close out the top-seeded Nationals with another victory on Thursday.
In front of an electric hometown crowd, however, the Nationals outlasted the Cardinals in a hard-fought pitchers' duel to force a decisive Game 5 on Friday. The two teams combined for just six hits (three each), but it was the last hit that lifted the Nats to victory.
With the score tied at 1 going to the bottom of the ninth, Jayson Werth stepped to the plate and delivered a leadoff walk-off home run. The shot was Washington's first hit since Ryan Zimmerman singled with one out in the fourth inning.
Fortunately for the Nats, their pitching matched that of the Cardinals'. After starter Ross Detwiler limited the Cards to just one unearned run over six innings, Jordan Zimmermann, Tyler Clippard and Drew Storen combined for three no-hit innings while recording eight of the final nine outs via strikeout.
Ironically, the last time the Cardinals lost a postseason game on a walk-off home run (Game 5, 2004 NLCS vs. Astros) was also the last time both teams recorded three hits or fewer in a playoff game. St. Louis went on to win that series in seven games en route to losing the World Series to the Red Sox.
American League DS Game 4: Orioles 2, Yankees 1 (13 innings)
For the second straight night, the AL East rivals treated fans to some extra baseball -- but there was no heroic walk-off tonight.
Instead the Orioles kept their Cinderella season alive by beating the Yanks, 2-1, in 13 innings to force yet another Game 5.
As was the case in the Nationals' victory, Baltimore simply outlasted New York in a pitchers' duel in the Bronx. The Orioles threatened with two runners on base in three of the first four innings, but didn't push across a run until Nate McLouth hit a solo homer in the fifth. The Yankees answered with a run on Robinson Cano's RBI groundout one inning later, then the game became a battle of the bullpens.
The back end of the Orioles' bullpen -- a key reason for their surprising run -- was at its best on Thursday night, stifling the Yankees throughout the extra frames. Darren O'Day tossed 2 2/3 no-hit innings, then handed the ball to Pedro Strop, who threw two scoreless frames for the win.
J.J. Hardy plated the go-ahead run on a 13th-inning double, and manager Buck Showalter showed faith in closer Jim Johnson in the bottom half of the frame. Johnson, who was tagged for five runs in Game 1 and blew the save in Game 3, retired the side in order to cement the victory.
After the two teams alternated victories through the first four games, will the Yankees continue that pattern en route to an ALCS berth, or will the Orioles' surprising run extend deeper into the postseason?
ALDS Game 5: Tigers 6, A's 0
For most of the season, the Tigers were considered underachievers, and there was genuine concern whether they'd even qualify for the postseason. The Athletics, meanwhile, exceeded just about everyone's expectations and earned one of the most surprising division titles ever.
Yet after Thursday night's do-or-die Game 5 victory, Detroit finds itself in the ALCS for the second consecutive year, and Oakland's incredible run has come to a dramatic end.
The A's entered the contest with momentum following Wednesday's ninth-inning comeback victory, which extended the series. But even momentum combined with playing in front of a raucous home crowd was no match for Tigers ace Justin Verlander.
Verlander made history with a masterful shutout after the Tigers rolled to a 6-0 win. In doing so he became the first pitcher to throw a shutout in an ALDS-deciding game. He also set a DS record, for either league, with 22 strikeouts.
Rookie Jarrod Parker turned in a respectable start opposite the reigning MVP and Cy Young winner, but Verlander had all the support he needed after the Tigers put across two runs in the third inning.
Detroit now will set its sights on avenging last season's ALCS loss to the Rangers. The only question is whether Game 1 on Saturday will come against the perennial power Yankees or the upstart Orioles.