American Meb Keflezighi, of San Diego, showed great fatigue in the final few miles but reached down deep and found the energy to stun the field at the 2014 Boston Marathon.
Keflezighi became the first American men's winner at Boston since 1983 (Greg Myer) with an official time of 2:08:37.
Onlookers chanted "USA! USA!" as Keflezighi crossed the finish line on Boylston Street, an emotional performance in a city still recovering from last year's fatal bombing attack during the world-renowned race.
Keflezighi, who was born in Eritrea but is now a U.S. citizen, pulled ahead of a pack of elite African runners a little more than halfway into the race and held off a late challenge by Kenya's Wilson Chebet, who finished second.
Here are the top 10 men's finishers, according to BAA.org:
1 Keflezighi, Meb 2:08:37 CA USA
2 Chebet, Wilson 2:08:48 KEN
3 Chepkwony, Frankline 2:08:50 KEN
4 Shafar, Vitaliy 2:09:37 UKR
5 Geneti, Markos 2:09:50 ETH
6 Kimurer, Joel 2:11:03 KEN
7 Arciniaga, Nicholas 2:11:47 AZ USA
8 Eggleston, Jeffrey 2:11:57 CO USA
9 Lonyangata, Paul 2:12:34 KEN
10 Annani, Adil 2:12:43 MAR
Among the women, Kenya's Rita Jeptoo notched her second consecutive win of the race, smashing a 12-year course record with a blistering official time of 2 hours, 18 minutes and 57 seconds, reeling in American Shalane Flanagan, who had led the women for the first 20 miles of the 26.2-mile race, setting a punishing pace.
Keflezighi said he had been extra motivated to win after seeing the attack last year.
"It was not just about me. ... I was going to give everything I could for the people," said Keflezighi.
Noting that the Boston Red Sox's World Series championship last year had lifted the city's spirits, he added that he wanted to provide a similar boost: "When the Red Sox did it, I said, 'I want to do it for Boston.'"
Flanagan, who finished seventh, gave a tearful television interview after the race.
"I love Boston so much and I really wanted to do it for this city," said Flanagan, who was raised in Marblehead, Mass. "I'm so sad I couldn't do it for Boston."
Here are the top 10 women's finishers, according to BAA.org:
1 Jeptoo, Rita 2:18:57 KEN
2 Deba, Buzunesh 2:19:59 ETH
3 Dibaba, Mare 2:20:35 ETH
4 Sumgong, Jemima 2:20:41 KEN
5 Melkamu, Meselech 2:21:28 ETH
6 Duliba, Aleksandra 2:21:29 BLR
7 Flanagan, Shalane 2:22:02 USA
8 Cherop, Sharon 2:23:00 KEN
9 Ongori, Philes 2:23:22 KEN
Three people, including an 8-year-old boy, were killed and 264 were hurt when two homemade bombs left at the crowded finish line of last year's Marathon exploded, tearing through the crowd. One of the two suspects is facing numerous charges and is awaiting trial; the other was killed during the manhunt in the wake of the bombings.
Fans had packed the course, waving American flags and wearing T-shirts bearing the "Boston Strong" motto the city adopted as a rallying cry after last year's attack. Their screams grew deafening as Keflezighi tore through the final miles.
"It is very symbolic that an American won this race today, one year after the bombing," said Veronica Carroll, who had traveled from New Jersey to watch her husband run. "It represents the strength of our country."
Some 35,755 runners from 96 countries competed in the second-largest field in history for the 118th running of the Boston Marathon.
Race organizers expanded the field by some 9,000 runners this year, to allow the roughly 5,000 athletes who could not finish the course last year after the twin pressure-cooker bombs went off near the finish line another chance to compete.