Boston Marathon Winner -- America Wins 2014 Race ... For First Time in 31 Years

Not just Boston strong ... but AMERICAN strong ... a San Diego native just destroyed the competition at the Boston Marathon -- becoming the first man from the U.S. of A. to win the race since 1983.

Meb Keflezighi, 38, crossed the finish line with an unofficial time of 2:08:37. In 2009, Keflezighi won the New York City Marathon ... and became the first American to win that since 1982.

Kenyan Rita Jeptoo snagged the win in the women's division with a time of 2:18:57 -- a course record. It's her 2nd straight win.

More than 36,000 runners took part in the Boston race this year -- 9,000 more than last year, when bomb explosions killed 3 people and injured more than 260.