Elsewhere, the Pirates won and the Giants lost, which had them deadlocked in the top two slots for the NL Wild Card. The Dodgers got closer to an NL West title and ensuring home-field in a Division Series by winning in Chicago on Sunday, but the AL East champion Orioles lost a day of momentum in that department by dropping a game to Boston and the AL West-winning Angels slipped up in their hunt for home-field advantage throughout the playoffs with a loss to Texas.
IF THE POSTSEASON STARTED TODAY ...
Wild Card: Royals at A's
Division Series: Wild Card at Angels | Tigers at Orioles
Wild Card: Giants at Pirates
Division Series: Wild Card at Nationals | Cardinals at Dodgers
• Postseason picture
On Sunday, the Cardinals learned they had qualified for the postseason by watching the Pirates win on TV. It was a foregone conclusion for a team that's built a somewhat comfortable 2 1/2-game lead over Pittsburgh in the NL Central, but St. Louis would like to seal up the division sooner than later. Still, the Cards could take a few moments, at least, to be proud of what they've accomplished so far.
"You can tell that it is a one-track mind right now," St. Louis manager Mike Matheny said. "It's, 'What do we have to do to win this division?' There will be a time, if things play out and we're able to go in as a Wild Card team, we will celebrate that, because there are a whole lot of teams that would like to be in this situation. But right now, we're also in a position to keep moving forward to try and win this division."
Neither the Tigers nor the Royals have yet qualified for the postseason because their division race is going down to the wire. On Sunday, Kansas City got a game back in the teams' last head-to-head meeting in the regular season, stayed firmly in the mix for the AL Wild Card when the Mariners lost to Houston, and proved that their remarkable season is hardly done.
"I think today's game showed that we're not going away," Royals manager Ned Yost said after Sunday's win. "They had that feeling this morning that they knew that this was going to be a big game. They had a lot of confidence in themselves when they hit the field."
In Oakland, the A's needed some confidence after a recent skid, and things were tight through nine innings, but in the bottom of the 10th, they got a major contribution and a dramatic moment from one of the offensive players they've been leaning on during their last two AL West championship seasons, Donaldson.
Across the bay, the Giants lost some ground to the Dodgers in the NL West standings but stayed right in the mix for the Wild Card. They're tied with Pittsburgh, but the Pirates would hold the home-field advantage in a Wild Card Game or tiebreaker because they beat the Giants in four of six games this season.
Either way, Pittsburgh has been playing as well as any team of late and took another big step toward October by beating Milwaukee on Sunday in its regular-season PNC Park bow. Now the Pirates venture away from Pittsburgh for their final week of hugely important games.
This week, the Angels and Nationals will try to keep their positions as the clubs with the best records in their leagues and ensure home-field advantage throughout their playoff runs. The rest of the contenders will try to win out and pull a surprise while the Wild Cards are sorted out in what will surely be a final-week frenzy.
TODAY'S KEY GAMES TO WATCH (all times ET)
Royals (Duffy, 8-11) at Indians (Carrasco, 8-5), 7:05 p.m. Preview
Before this game starts, the two clubs have to finish up their suspended game from Aug. 31, which Cleveland currently leads, 4-2, in the bottom of the 10th. The Royals will hand the ball to their hard-throwing left-hander, Danny Duffy, in hopes that he'll be able to contain the Indians' offense, but Cleveland starter Carlos Carrasco has been brilliant of late and the Royals will be on the road, so it's a tall order.
Mariners (Paxton, 6-3) at Blue Jays (Happ, 9-11), 7:07 p.m. Preview
The Mariners need as many wins as they can get right now, and their young left-hander, James Paxton, has been one of their best pitchers over the past few weeks.
White Sox (Bassitt, 0-1) at Tigers (Lobstein, 1-0), 7:08 p.m. Preview
Detroit will be looking to take advantage of playing at Comerica Park and will rely on Kyle Lobstein to push it one game closer to winning the AL Central.
Pirates (Liriano, 6-10) at Braves (Harang, 11-11), 7:10 p.m. Preview
The Pirates are closing in on a Wild Card berth, but they won't play another regular-season game at home. In other words, it's crunch time, beginning tonight in Atlanta.
Cardinals (Wainwright, 19-9) at Cubs (Wood, 8-12), 8:05 p.m. Preview
Adam Wainwright can win his 20th game of the year and get his team closer to a division title.
Angels (Wilson, 13-9) at Athletics (Samardzija, 6-12), 10:05 p.m. Preview
The A's might have recaptured some magic at home on Sunday with a walk-off win over Philadelphia. They'll be looking to tap into that mojo against the Angels.
Giants (Peavy, 7-13) at Dodgers (Haren, 13-11), 10:10 p.m. Preview
The Dodgers' magic number to clinch the NL West is only at three, so the Giants need to win beginning tonight to have any shot at pulling out a division title.
• Watch the races on MLB.TV
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.
AL East: Orioles clinched
AL Central: Tigers seven over Royals
AL West: Angels clinched
AL Wild Card 1: A's eight over Royals
AL Wild Card 2: Royals seven over Mariners
NL East: Nationals clinched
NL Central: Cardinals five over Pirates
NL West: Dodgers three over Giants
NL Wild Card 1: Pirates eight over Giants
NL Wild Card 2: Giants three over Brewers
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