Sparked by Madison Bumgarner's historic pitching performance on only two days' rest, San ­Francisco won their third World Series in five ­seasons by beating Kansas City 3-2 on Wednesday.

The Giants won Major League Baseball's best-of-seven final 4-3, claiming their eighth overall championship and following up 2010 and 2012 titles by taking an intense winner-take-all showdown that was dramatic to the last play.

Bumgarner, a 25-year-old left-hander who mystified Royals batters in winning games two and five, pitched five scoreless relief innings, striking out four while allowing only two hits and throwing 50 of his 68 pitches for strikes on career-low rest to earn unanimous Most Valuable Player honors.

"I wasn't thinking about innings or pitch count. I was just thinking about getting outs, getting outs, until I couldn't get them anymore," Bumgarner said.

Bumgarner, originally credited with the game-seven win before an official scorer's change gave him only a save and handed Jeremy Affeldt the win, allowed only one run in 21 World Series innings with 17 strikeouts and only one walk.

In 36 career World Series innings, Bumgarner has a record-low earned-run average of 0.25 and his 52 2/3 playoff innings pitched this month was a record, breaking the old mark of 48 1/3 by Curt Schilling in 2001.

History had favored the Royals as home teams had won the previous nine World Series game sevens, no road team having taken a one-game showdown for the crown since Pittsburgh at Baltimore in 1979.

The Giants entered 0-4 in winner-take-all World Series games, having lost final title contests in 1912, 1924, 1962 and 2002.

They became the first World Series road team since the 1975 Cincinnati Reds to lose game six but recover to win game seven.