AFP/Chicago

With the win, the Royals assured themselves of at least an American League wild-card spot—their first post-season appearance since they won the World Series in 1985.

Nori Aoki, Lorenzo Cain and Billy Butler each drove in a run in a three-run first inning, and that proved to be all the offense the Royals needed.

Starting pitcher Jeremy Guthrie tossed seven scoreless innings, limiting the White Sox to four hits and one walk with six strikeouts.

‘’It feels better than expected,’’ said Billy Butler, a 2004 draft pick and eight-year veteran. ‘’It’s a great thing. I’m proud to bring this organization something they envisioned when they drafted me.’’

Not only are the Royals assured of playing at least the one-game, wild-card round, they are just one game behind the Detroit Tigers in the race for the American League Central division crown, after their victory coupled with the Tigers’ 11-4 loss to the Minnesota Twins.

In Detroit, Brian Dozier went 3-for-5 at the plate with a home run, three runs-batted-in and three runs scored to help Minnesota to the win.

Danny Santana also collected three hits and scored twice, Oswaldo Arcia homered and Kurt Suzuki drove in two runs for the Twins.

The Tigers could have clinched their fourth consecutive AL Central title with a victory and a loss by the Royals, but now the race will come down to the final two games for each team this weekend.

If they finish tied in the standings, the Royals and Tigers would contest a one-game playoff on Monday for the division crown.

Elsewhere, Josh Reddick had a home run and three RBIs and the Oakland Athletics moved to the verge of a postseason spot with a 6-2 victory over the Texas Rangers.

Reddick, who went 2-for-4, hit his 12th home run of the season and the Athletics (87-73) remained one game behind Kansas City (88-72) for the first American League wild-card berth.

The Seattle Mariners needed three home runs and a strong pitching performance from starter Hisashi Iwakuma and four relievers to finish off their first must-win game of the season with a 4-3 victory over the Los Angeles Angels.

Seattle (85-75) stayed alive in the American League wild-card hunt, two games behind Oakland with two games remaining.

The Mariners survived a shaky top of the ninth inning that saw All-Star closer Fernando Rodney give up two hits and a run.

Doug Fister, in his final tune-up for a postseason start, allowed just three hits in his second career shutout as the Washington Nationals beat the Miami Marlins 4-0 in the first game of a doubleheader.

The win secured home advantage throughout the National League playoffs for the Nationals (94-65), the East division champions, who have won nine of their last 11 games.

Fister (16-6), acquired in a trade with the Detroit Tigers in December, won his fourth straight start and has allowed just four earned runs in that time.

Kike Hernandez hit a grand slam, the first of his career, and J.T. Realmuto had three hits and four RBIs as the Marlins pounded out 22 hits to defeat the Nationals 15-7 and earn a split of the doubleheader.