Jeptoo, whose 2006 and 2013 victories remain unchallenged, is the first person to break the tape on Boylston Street and be disqualified since Rosie Ruiz famously took a shortcut to the finish line in 1980.
Although the marathon's profile reached a pinnacle of worldwide notoriety in 2012, due to the terrorist bombings, there have also been very memorable moments on "marathon day" even since then.
In the women's race, Kiplagat conjured a similarly decisive burst over the closing stages to claim the race for the first time.
Another notable race was in 2014.
The 121st Boston Marathon takes place Monday, and two Portland-based, ex-University of OR runners figure to be in the thick of the battle for individual titles.
He pledged to run four marathons in three weeks in memory of his dad who was killed in a crash in his hometown of Coventry.
Half a century ago, Kathrine Switzer signed up to run the Boston Marathon with her initials: K.V. Switzer. "I knew I would challenge some of the champions who have been competing here". "I had the best job in the world for a long, long time".
The warm temperatures that hit 79 degrees at the 20-kilometer mark in slowed the runners but the strong tailwind was a boost - especially for the wheelchair races.
Fellow Swiss Marcel Hug took the men's race in 1:18:04, also the fastest time ever.
Manuela Schar of Switzerland finished in 1 hour, 28 minutes, 17 seconds - shattering the world best by more than five minutes.
Keflezighi, who plans to retire from racing after this year's NY marathon, stopped after his victory to touch the hand of Bill Richard, whose 8-year-old son Martin was the youngest person to die in the bombing.
"The wind is so important", Hug said.
Sanchez ran his first marathon in Washington D.C.in 2015. "Everything was fantastic today".
"It's my last [Boston] Marathon - what do I have to worry about?" This year, some of those the pack included a formerly homeless man who was running to raise money for a homeless shelter, and Ben Beach going for an unprecedented 50th straight Boston finish.
It was Evan's 19th time completing the race and his 52nd overall marathon.
Earlier Monday, city officials announced plans for memorials to mark the sites where two bombs exploded during the 2013 race. "And I saw that he had not come with me, so I pushed a little bit more".
This morning, more than 30,000 souls will cram into the relatively small space of downtown Hopkinton, anticipating a 26-mile, 385-yard journey to the John Hancock Tower in Boston.