British Olympic champion Mo Farah finished eighth on his marathon debut as Kenyan world record holder Wilson Kipsang won his second title in London.
Farah, 31, failed to break Steve Jones's 29-year-old British record of two hours, seven minutes 13 seconds and finished in 2:08:21.
Kipsang set a course record 2:04.27 with compatriot Stanley Biwott second.
Edna Kiplagat pipped fellow Kenyan Florence Kiplagat in the women's race with debutant Tirunesh Dibaba third.
Farah elected to sit among the second pack of elite runners, but soon found himself 38 seconds behind the lead group, headed by Kipsang, at the halfway mark.
That gap increased to 49 seconds after 15 miles and then over a minute by the time they reached 19 miles.
Despite missing out on the British record, Farah recorded the fourth fastest time by a Briton and set the fastest time by an Englishman.
Asked if he would do another marathon, Farah, who finished almost four minutes behind the winner, said: "Yeh, definitely, 100%. I'm not going to finish it like this. I will be back.
"I would have been disappointed to do my first marathon somewhere else. I gave it my all but I just wish I gave a little bit more to the crowd and all the supporters.
"It was pretty tough. I'm quite disappointed but you try things and if they don't work, at least you gave it a go. It was really just the pace - I should have gone with the front group. The pacemakers I had were slightly ahead of me but you learn - life goes on."
Former British world champion Paula Radcliffe believes Farah made the correct decision in choosing to make his marathon bow in London.
"If you are a British runner and you want to attack the marathon, you do it in London, there is no better stage," she told BBC Sport.
"The plan was to go through the first half at slower pace and that was what he did, but he wasn't quite able to come back in the second half of the race. I think he has found out what the marathon is all about."
Farah has yet to decide whether he will return to the track in time to compete at the Commonwealth Games, which begin on 23 July.
Race winner Kipsang, who set the world record of 2:03:23 in Berlin last year, stayed among the lead pack until he and countryman Biwott broke away with just over six miles remaining.
In the last two miles, Kipsang showed his class to ease away from the 2012 Paris champion and eventually finish 26 seconds ahead of his rival.
"I took advantage of controlling the pace and the guys," Kipsang, who also won in 2012, told BBC Sport. "I saw that Biwott was really strong. It was becoming more tricky. My main target was to win and run a course record."
Briton Chris Thompson, who took 10,000m silver behind Farah in the 2010 European Championships, finished 11th on his marathon debut in a time of 2:11:19, well inside the qualification time for both the Commonwealth Games in July and European Championships in August.
Meanwhile, the women's race developed into a three-way fight between the Kenyan pair and marathon debutant Dibaba, the Olympic 10,000m champion, until the Ethiopian made a mistake at a drinks station that cost her about 15 to 20 metres on the leading pair.
They then battled neck-and-neck until the final 150m when Edna Kiplagat outpaced Florence Kiplagat to win by three seconds in a time of 2:20.21.
Amy Whitehead and Emma Stepto were the first British women home in 13th (2:34.20) and 14th (2:36.05) place respectively.