Norichika Aoki of the Kansas City Royals gets hit in the MLB game against the Baltimore Orioles in Kansas City, Missouri on Wednesday (US time). Photo: AFP

Unbeaten in their first Major League Baseball playoffs since 1985, the Kansas City Royals advanced to the World Series by defeating the Baltimore Orioles 2-1 on Wednesday (US time).

The Royals, who won their only World Series title 29 years ago, became the first Major League Baseball team to win their first eight playoff games in a season by finishing off a four-game sweep of the Orioles in the best-of-seven American League finals.

"It has been awesome," Royals slugger Eric Hosmer said. "But we're not done yet."

Kansas City will host the ­National League winners, ­either the St. Louis Cardinals or the San Francisco Giants, in game one of the best-of-seven championship finals on Tuesday.

San Francisco rallied from a three-run deficit on Wednesday to defeat the Cardinals 6-4 and seized a 3-1 lead in the best-of-seven National League finals.

Should the Royals win their World Series opener, they would equal the all-time longest major league playoff multi-year win streak - 12 games - set by the New York Yankees between 1927 and 1932 and matched by them in 1998-99 - even with a 29-year gap between wins three and four.

The Royals captured the 1985 World Series by winning the final three games to defeat Missouri state rival St. ­Louis ­after the maximum seven games.

Since then, Kansas City fans had suffered the longest drought of any major league team without a playoff game, but were rewarded for their patience this month when the Royals beat Oakland in the wild-card game, swept the Los Angeles Angels in the best-of-five division series and dispatched an Orioles squad seeking its first World Series berth since winning in 1983.

"It's not like something we didn't do," Orioles manager Buck Showalter said. "It was more like what they did."

It was the first time the Orioles had ever been swept in a playoff series, having dropped two one-run decisions on the road and a pair of two-run decisions at home with both games level after eight innings.

"We don't feel like we played bad. They just played better," Baltimore's J.J. Hardy said.