Now comes the next task at hand -- winning the American League West.
The Rangers will get their first chance Monday night in Oakland against the second-place A's, needing one win in three games against a red-hot opponent. The Rangers take a two-game lead into Oakland against an A's team that right now is positioned to win the second Wild Card.
The Rangers had a toast of champagne before departing for Oakland late Sunday night, but that was it.
"I don't think we should celebrate," said third baseman Adrian Beltre, who left Game 2 of Sunday's doubleheader with an aggravation of a left shoulder strain. "This year the Wild Card is just a one-game playoff, so even if you win the Wild Card, you're not in yet. So I'm glad we get another shot in case something happens but we never had in mind the Wild Card. We had in mind the division."
The Rangers endured a decent amount just to clinch at least a Wild Card. They could have clinched as early as Friday, but lost to the Angels, 7-4. Then came the rain on Saturday as they sat around all day until what was scheduled for a 3:05 p.m. CT start. The game was postponed four hours later, setting up Sunday's day-night doubleheader.
Game 1 on Sunday saw the Rangers take a 4-3 lead into the ninth inning, only to have Torii Hunter's two-run double to left-center field ruin their chance to celebrate and maybe play to clinch the AL West title -- had the A's lost to Seattle (Oakland won, 5-2).
The Rangers fell behind, 4-0, in the first inning of Game 2, but ex-Angel and current Halos-killer Mike Napoli belted two home runs and had six RBIs to help rally his club to a much needed win and chance to relax for a moment.
"It was huge," Beltre said. "The first game it was a little bit upsetting for us but we got behind the first inning, 4-0, and come back was huge for us. And to be able to hold the lead the one-run lead was huge for us. We didn't want to go to Oakland and have to win two to win the division. It's not done yet, but it's a lot easier to have to win one and not two."
Today's key games to watch (all times ET)
Rangers (Perez, 1-3) at A's (Parker, 12-8), 10:05 p.m. Preview >
Red Sox (Buchholz, 11-7) at Yankees (Sabathia, 14-6), 7:05 p.m. Preview >
If the postseason started today ...
This is how the teams would match up: Postseason Bracket »
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 the 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 the division record will be the next tiebreaker.
2012 postseason schedule
Wild Card playoff games: Oct. 5
Division Series: Oct. 6-12
AL Championship Series: Oct. 13-21
NL Championship Series: Oct. 14-22
World Series: Oct. 24-Nov. 1
Todd Wills is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.