BOSTON — With a brisk wind at his back and a determined countryman on his shoulder to push him down the stretch, Geoffrey Mutai of Kenya pulled away from Moses Mosop in the final quarter-mile Monday to win the 115th Boston Marathon. His time, 2 hours 3 minutes 2 seconds, was the fastest marathon run by nearly a minute, and it smashed the course record, set last year, by nearly three minutes.

Mutai, running the hilly 26.2-mile course for the first time and in ideal conditions, beat the internationally recognized world record, 2:03:59, set in September 2008 in Berlin by Ethiopia’s Haile Gebrselassie, who benefited from having pacesetters. Boston does not allow pacesetters.

Mosop finished four seconds behind Mutai on Monday.

The time is not considered a world record, however, because the Boston course is not sanctioned as being record-eligible by the International Association of Athletics Federations, track and field’s world governing body.