Kenya's John Korir set a new course record of two hours, one minute and 52 seconds to win a second successive Boston Marathon.
Compatriot Sharon Lokedi also defended her title in the women's race, finishing in two hours, 18 minutes and 51 seconds.
Korir, 29, shaved one minute and 10 seconds off the previous course record set by Kenya's Geoffrey Mutai in 2011.
His latest victory follows wins at the Chicago Marathon in 2024 and the Valencia Marathon in December.
"This year was a breeze for me because I had no problems at the start or at the finish," Korir, who fell early before recovering to win last year's event, said.
"It felt like a race back home with all the people cheering. It was in my mind to set the course record and I thank God that he fulfilled my wishes."
Korir's time is the fifth fastest marathon run on record.
Lokedi was unable to break her course record of two hours, 17 minutes and 22 seconds, which she set last year, but crossed the line 44 seconds clear of fellow Kenyan Loice Chemnung in second.
"I just kept telling myself 'Be patient, be humble, you can do this'," Lokedi, who won the 2022 New York Marathon, said.
"And then I saw a little girl who said 'You got this, ladies!' And it was so cute, and that was what I needed."
Britain's Calli Hauger-Thackery, who is 22 weeks pregnant, completed the race in two hours, 43 minutes and 58 seconds.
Hauger-Thackery, 33, won the Honolulu Marathon when four weeks pregnant and won the Houston Marathon one month later.
