RECORD RUN . . . Former Stanford All-American Ryan Hall helped make the 114th running of the Boston Marathon the fastest ever on Monday. While Hall became the fastest American in the history of the race with his fourth-place finish, Robert Kiprono Cheruiyot of Kenya put on a dominant performance to clock the fastest time ever in the event. On a gorgeous morning, with temperatures in the low 50s and a wind that was more favorable than not, Cheruiyot put the pedal down in the 16th and 17th miles, breaking away with defending champion Deriba Merga. Despite a gimpy hamstring, Cheruiyot then dropped Merga to win in 2:05:52. Only 21 years old, Cheruiyot crushed the course record of 2:07:14, run by four-time Boston champ Robert Kipkoech Cheruiyot in 2006. Tekeste Kebede of Ethiopia moved up to finish second in 2:07:23, with Merga third in 2:08:39. Hall ran a race eerily similar to his 2009 Boston effort, leading the pack almost from the gun. At various points in the race, Hall dropped back into the pack only to resume the lead, but at 10 miles he had dropped 10 seconds off the lead while American 2004 Olympic marathon silver medalist Meb Keflezighi held steady with the pack. Hall slowly worked back as the pace flagged to 5-minute pace at mile 11, but the hammering of Cheruiyot and Merga of 4:38 and 4:42 miles broke up the pack for good. After dropping to sixth, Hall moved back up to place fourth in 2:08:41, the fastest time by an American at Boston. Bob Kempainen ran 2:08:47 to place seventh in 1994. "Today was a breakthrough day," said Hall, 27. "Guys are paving new territory, and that's good for us, too."